December 16, 2011

Where plus-sizing is super-sexy

Some men like them super-sized. And we're not talking about women, or any part belonging to women. We're talking about the rims of car wheels. Car wheels? Why yes: for many cars, plus-sized wheels are a rather expensive option that has mystified CelloMom for some time now. Why are wheels with wider rims worth a premium up to $5000?

In case you are completely confused: Plus-sizing refers to the option of buying wheels for your car with larger-diameter rims. For instance, if the "standard" package has wheels with 16" diameter rims, the option with 17" rims is called Plus-1, that with 18" rims is called Plus-2, and so on. The picture below shows five out of 14 choices offered for the Audi A6 Saloon (Europe-speak for Sedan), culled from the German price list. Way on the left is the standard wheel with 16" rims, the next one is Plus-1, then Plus-2 and Plus-3, and finally on the far right is the Plus-4 tire with 20" rims. Don't ask why a German carmaker like Audi measures its wheel rims in inches, that one is way beyond Cellomom.

You can change the size of the tire rim, but you must keep the overall wheel diameter unchanged, or your speed indicator and mileage counter will be inaccurate. So as you go from a 16" rim to a 20" rim, the tires' sidewall gets smaller by 2"; you can see this trend clearly in the picture above. At the same time, the wheels get wider in the lateral direction (left-right direction of the car). Typically the recommended pressure is a few psi higher for Plus-1 tires.

So that's the what. But why? CelloMom finds that the benefits of plus-sizing falls in two categories: performance and aesthetics.


Performance, the Pros
"Performance" in this context means better handling. That's code for being able to zip around corners better and faster (on dry roads anyway), and to reach higher maximum speeds.

Response time:
Because plus-sized tires have a smaller sidewall, the tire distortion that happens when you go around a corner is reduced, and you can change direction that much faster.

Better traction (on dry roads):
The weight of the car makes the tires sag a little. With smaller sidewalls and higher pressure this distortion is reduced, so the contact patch, where the tire touches the road, is shorter in the tangential direction, or the front-back direction of the car. But the tire is also wider, so the contact patch is wider laterally. Because that is not the rolling direction, this gives better protection against skidding. With a plus-sized tire, instead of starting to skid at 0.83g, you keep frictional road contact until 0.88g (from a Car&Driver test).
Zow. At these accelerations, without seat belts the passengers would be banking the corner sitting at nearly 45 degrees from the usual vertical. Eggs and cellos can be written off.

Higher maximum speed:
Some physics connected with the shorter and wider contact patch (which CelloMom doesn't understand) allows plus-sized wheels to reach higher maximum safe speeds. We're talking an improvement from 150mph to 170mph. Since both these speeds are more than twice the US highway speed limit, CelloMom can't be bothered to dig up the relevant physics.


Performance, the Cons
These performance improvements come at a price. Here is the other side of the argument:

Fuel economy suffers
Plus-sized wheels are heavier than standard ones. In the Car&Driver test going to Plus-4 resulted in a 10% decrease of fuel efficiency.

Bumpy ride
Because the tires' sidewalls are smaller, and because the pressure is higher, plus-sized tires don't absorb any unevenness in the road surface, so you'll feel connected to the road in more ways than one. The shock absorbers in the suspension system are optimised for a lower frequency range, so they won't help much on gravel, unpaved roads and other conditions which are unknown on race courses.

Worse traction in snow and water
Plus-sized tires are wider, so squeezing surface water away through the treads is harder. The result is that it's much easier to start hydroplaning in rainy conditions. And because the contact patch is shorter in the direction of travel, and also because of the higher tire pressure, traction is worse in snowy and icy conditions.

Wheel damage
You know what they say about wheels: when you bend it you can't mend it. A reduced side wall on a tire makes the tire more prone to rupture, and is the shortest way to a damaged rim. In the 2010's US, roads are not only not smooth, they are downright dangerous to the well-being of wheel rims. Never mind the broken glass and the rusty nails: CelloMoms town sports potholes large enough to do the cooking for half a village. And while potholes are merely deep, what's arguably even more dangerous are manholes which have inexplicably sunk into the asphalt, making nice paella pans. Some of those are deep enough to feed half the village also, and sport nice sharp and well-defined edges that will cheerfully put an end to the circularity of your wheel.

Which brings us to the funds required to acquire (or replace) the wheels. For the Audi A6 example, the 16" wheels come standard. Getting successively larger wheels gets more expensive. The most expensive 20" wheel is a €3650 option ($4700 at today's exchange rate).



Okay. That was function; how about looks? CelloMom did a small and non-scientific survey among her friends, who were all mystified as to why larger wheel rims are considered more attractive. So, maybe that just means that we are not in the tribe of car enthousiasts. CelloMom asked around at various dealerships, figuring the people who sell those expensive options might have a clearer idea. But the best she got from this (also small) survey is this statement from one dealer, delivered firmly: "The car enthousiast (such as myself) prefers the look of a smaller sidewall." The Car&Driver article on plus-sizing starts by stating, "The aesthetic appeal of larger wheels and tires is undeniable". That didn't help CelloMom at all.

But cruising around the car world, eventually you run into cars that someone like CelloMom would not ordinarily drive. Check out this Ferrari: in this incarnation you can barely even see the tires, because the rims themselves practically fill the wheel well.

A light went on in CelloMom's head: "aesthetics" just means making your car look more like a Ferrari. Even if you never approach 170mph, even if you never take corners at close to 1g centrifugal force, the idea that you look like a Ferrari at all times is still worth a lot - up to $5000, in fact.

One good reason to have a large wheel rim in a race car, besides the improved road-tire interaction, is the dissipation of heat. At high speeds and large accelerations (including deceleration), wheels heat up from the road contact, and braking produces a lot more heat than in ordinary road conditions. CelloMom is not into watching car races, but heard that in some night-time races you can see the wheels glow from the heat generated by the brakes. So you want to design your wheels with a central area that is as large and as open as possible, perhaps also fiddling with the spoke design to whisk away all that heat.

You will notice that, for the sequence of Audi A6 tires, as you go from 16" to 20" the wheels become more open. For the 19" wheels (see picture below) you can look right in, reminding CelloMom of a cathedral window: open, beautiful, and very delicate.

Audi A6, 19" wheel. Rose window in San Vigilio, Trento, Italy

Call CelloMom a nerd. (She won't deny it.) When it comes to cars, she is overwhelmingly more sensitive to actual function than to looks or ideas. She never lives in the conditions where the improved performance of plus-sized wheels would make a difference. She's more than happy to drive in a vehicle with the regular set of tires: More rubber between the rims and the road means more protection from things like rattling teeth, dented rims, ice-skating cars, and the depletion of the purse. We'll take it.

December 14, 2011

Preview: Volvo V60 Plug-in Hybrid

CelloMom can forget about a test drive in this one: There are just a handful of them for sale in 2012. Volvo plans to make 1000 of them for 2013, and 5000 in 2014 (!) of which 30% will remain in Sweden, and the rest doled out to other European countries. But the specs on this baby are enough to make you want to buy a ticket to Stockholm. Certainly enough to make your green-leaning heart beat wildly with desire.

Developed by Volvo and the Swedish energy provider Vattenfal, this is a hybrid with a twist: The five-cylinder 2.4L turbodiesel engine drives the front wheels at 215HP. The 70HP electric engine lives in the back: to be precise, between the rear wheels which it drives. Logical, no? The drawback is that the battery takes up the space where formerly the spare tire used to live. Check out the autoblog.nl gallery for nice cut-out images of the engine placement, as well as other photos, e.g. for the truly distracted among us, the dashboard backlight goes from blue to green to red as your fuel is depleted (no knowledge of Dutch required: these are pictures).

There are three buttons on the dashboard for choosing your driving mode: In the "Power" mode the turbodiesel engine gives that kick (from 0-100kph in 6.9 seconds, if you're into that kind of thing). One would have to be careful when carrying the cello, or eggs. In the "Pure" mode the electric engine does all the work (all 70HP of it); its range is up to 50km (30miles); charging it on a 230V outlet takes 7.5 hours at 6 Amps, or 3 hours at 16 Amps.

The "Hybrid" mode is the intermediate mode that gives the high fuel efficiency. CelloMom hopes you will not be taken in by the 124mpg number, since European fuel efficiency tests are wildly optimistic especially for the most frugal cars. For instance (see table below), the most frugal non-hybrid version of the V60 (which is also unavailable in the US) is the DRIVe with its 1.6L turbodiesel engine and a fuel economy quoted as 52mpg. In real life, as reported by real drivers, this model gets 39mpg, really not bad for a car of this size and weight.

Remembering that official European fuel economy numbers can be off by up to 40%, CelloMom's guess for the Volvo V60 plug-in hybrid is that its real fuel use will be in the 65-80mpg range.

Is 80mpg for the hybrid versus 39mpg for the turbodiesel enough to justify the price difference? Well- no. At European gas price levels, which have been around $10/gal (give or take a few bucks) you would be saving about $18,000 if your drive the car for 150,000 miles. That only accounts for half the price difference. At least another €4,000 (US$ 5,200) is because the "Kinetic" trim quoted in the table is the least expensive option, whereas the "Pure Limited" trim is bound to have all the bells and whistles, and then some. After all, this is a "Limited" edition, aimed at business use. The rest of the price difference can probably be chalked up to the novelty coefficient.

CelloMom, who is not an early adapter, prefers to wait until the kinks have been ironed out, and the price has come down once the widget has been made available to the masses. You can passively hope that this car will eventually make its way to American shores, or you can start talking to your Volvo dealer now to let them know that you want this baby!


Volvo V60 Estate, Turbo-Diesel vs. Plug-in Hybrid

TurboDiesel Plug-in Hybrid
Type DRIVe "Kinetic" "Pure Limited"
Year 2012 2012-2013
Emissions rating EURO5 "A"  
MSRP € 36,695 ($49,150) € 64,695 ($84,100)
CelloMom Rating *
Fuel Economy:
City/Hwy quoted 5.2 / 4.1 L/100km  
Avg. quoted 4.5L/100km (52mpg) 1.9L/100km (124mpg)
Avg. actual 39 mpg (Honest John) EST. 65-80 mpg

1.6L 4-cyl. turbo

2.4L 5-cyl. turbo
Power 115HP @ 3600rpm 215 HP (diesel)
70 HP (electric)
Gears 6-spd man 6-spd auto
Fuel Diesel Diesel
Length, mm(in) 4628mm (182.2in)  
Width, mm(in) 1865mm (73.4in)  
Height, mm(in) 1484mm (58.4)  
Weight, kg(lbs) 1537 kg (3389 lbs)  
Trunk volume, liters(cuft) 430 L (15.2 cuft)  
Turning radius, m(ft) 11.5m (37.7ft)  
Top speed, kph(mph) 190 kph (118mph)  

December 9, 2011

Can you do without the - now optional - spare tire?

Personally, CelloMom could do without the spare tire. But what about one for a new car? Very, very quietly, carmakers have stopped including a spare tire in their new vehicles. After all, taking things away can't be done with the same fanfare as when adding new features. Can you just see the ad? Cue deep male voice: "The NEW and IMPROVED Jeep Wrangler, now WITHOUT spare tire: because we want YOU to enjoy the extra 0.05 mpg!"

Most modern cars do get increased fuel efficiency when their rears are as smooth as possible - which is why they had the spare in the trunk.

Taking the spare out of the trunk decreases the total weight of the car by about 25lbs, or less than 1 percent of the total curb weight, from around 2500lbs for a small car like the Fiat 500, to over 4000lbs for a minivan. Don't buy the carmakers' tearful argument that they were driven to remove the spare tire by the harsh requirements of the new fuel efficiency standards: that argument doesn't wash.

What are your options? You can settle for the inflator kit that is offered for free. You can buy the optional "donut", a nearly-roadworthy torus that allows your car to limp to the nearest garage. You can buy a full-size spare tire, for up to $300. You can, on some models, opt for a set of "run-flat" tires, which can get you to the next garage even when completely flat, without damage to the rims. Those cost quite a bit more than $300.

There's the real argument: it's a cost-cutting measure. They make you pay $300 for something that they used to throw in standard and for free. And then they have the chutzpah to crow that there is suddenly SO much extra space in the trunk.

CelloMom will always opt for the full-sized spare. The roads and streets around where CelloMom lives are just not cleaned often enough or well enough. CelloMom is blessed with a flat tire about once a year, usually on some quiet road where it's nice that you can get yourself back on the road. CelloPlayer is getting pretty good at those tire bolts. If it ever happens on a highway it would be better to call AAA for help: it's just too dangerous to be messing around when just a few feet away traffic goes by at 65mph.

CelloMom found out about this spare tire issue when helping her dad buy a new car, over the summer in Holland, where he lives. He was offered, and refused, the option of the full-size spare. CelloMom was amazed. Here was a guy who is seriously into backup (that, anyway, is his excuse for owning three rather complete sets of tools). On one trip he brought a spare cylinder head; he put up with the teasing, until the spare ended up saving the trip. On certain road trips, like those in Indonesia, he is not happy until he gets at least two cars to go. With a spare tire in each car. And here he is saying no to a spare tire for his new car?

"You're just too stingy to cough up the 200 Euro", CelloMom said. We like to tell each other the truth. He turned around, and said,

"I haven't had a flat in forty years."

Whoa. CelloMom's dad loves his car. He regards it as an extension of himself. He digs the whole motel deal, where you can sleep right next to your car, but camping is better, because you can sleep in your car. He goes nowhere without that car, even though he lives in a country with excellent public transport and even better bike paths. He logs the miles. Okay, so Holland is a small place: but that's not where he rakes up the miles. Until CelloMom's mom passed away, they used to be on the road, all over Europe, for a minimum of five weeks a year. In a camper, mostly. By far their biggest vacation expense was gasoline.

Forty years of car travel like that, and not one flat? Either he's improbably lucky, or the roads are just cleaner over there. Or both.

December 8, 2011

Keeping up the pressure

Since CelloMom has pledged to warm herself up in the mornings by moving rather than turning up the thermostat, the yard has started to look mighty tidy. The carport is next, but first it's the turn of the car itself, on which the tires are looking a bit soft.

See this widget?

It's a bike pump adapter; you can get it at your local bicycle store. CelloMom got hers at a Dutch market (veggies, flowers, bike parts; all you need really). It cost one Euro, which today is about $1.50, and tomorrow might be anything, depending on whether or not the Europeans manage to keep themselves together monetarily.

But we digress. The pump adapter, which usually lives in CelloMom's spare change purse, goes on the tire valve and makes it look like a bicycle tire valve. Out comes the bike pump, and in goes the air. When CelloMom was done it was suddenly no longer a crisp morning, but rather a mild day - very mild for December. Those tires really were soft; shouldn't have let it go this far.

For $1.50 (and a bike pump, which was already in the shed), you can save the $1 you need to feed the air pump at the gas station, plus $10, the daily cost of a gym membership, and a chunk of the heating bill for today. Now that's a win.

December 2, 2011

Bring back the light!

Check out this German jousting armour. This is Protection with a capital P! The plates are good and heavy. The helmet has slits for eye openings, to keep the knight's eyes from being gouged by the opponent's lance, as he is aiming to dislodge the crest from the helmet. If the opponent is wearing similar armour, his vision wasn't all that good, so aiming that lance is a tricky business.

Fast forward to the present: When buying cars, we check out the safety ratings, because in the case of an accident we need the frames of our cars to give protection to ourselves and to our children.

But times have changed. CelloMom can't remember the last time she saw a jousting knight thundering out of the woods and onto the two-lane roads in her town. Can you? -- So why are the windows by the back seat getting smaller by the year?

As an example, consider the Honda CR-V, one of those CUVs much favoured by women. One assumes that a decent fraction of those women are moms who use their CR-V for ferrying their children. In a 1998 CR-V children had a glorious view out of their window. As long as you were in a child seat, you could still see down to road level.

Those children would not be happy if their mom bought a 2011 CR-V to replace her old trusty one from 1998. Just as the kids have grown from tots to teens, the window area in the back row has shrunk - by quite a lot. The bottom of the window frame has been raised, and the top of the frame is lower. Not only that, the third window has shrunk to the size of an afterthought. Now that the children have grown to who knows what heights, they would have no trouble looking down to the road surface, but they couldn't see the sky without some creative contortions on their necks, or else they have to do what you keep telling them not to do, which is to slouch way down on their seats.

Why would a car designer do this? Surely not to please the children in the back seat, but rather their parents, who after all are the ones who have to sign the financing papers. It has been suggested that when the bottom of the window frame follows a rising line towards the rear of the car, it makes the car look more sporty. Hmm. CelloMom could do without that one. CelloMom is all for her self being sportier than her car.

So the top of the window frame follows a downward sloping line, from the front to the rear of the car. If the roof were made to slope that way also, there is a very good aerodynamic reason for it, since the downward curve actually contributes to the fuel efficiency. Some models just end up looking like a large gorilla has been sitting on the rear end of the roof. On cars like the Toyota Prius or the Honda Insight, not only does the curved-down roof look pretty, the outline of the car resembles a leaf which pleases the green-leaning buyers.

But what to think of a car of which the windows follow the downward curve, while the roof stays reasonably flat? The Toyota Matrix is one of many examples. The overall assembly looks pretty enough. But then you get a nagging feeling that it's only appearing to be aerodynamically correct without actually being so. Reminds you of those politically correct university science departments whose websites trumpet their women-friendliness but whose sole female faculty member can be found in a lab in the basement.

At last, in 2012 the Matrix has a roof that actually curves down, so that the line of the roof follows the line of the windows. But the children on that back seat had better not grow to basketball players. Besides, they've taken away the third window altogether, so sitting in the back now feels like occupying a cave. Because the bottom line of the window frame is still tilted up.

But - the whole point of a car ride is to look at the world outside. Even on the daily ride to school, somehow there is something interesting to see every day.

Children in the back of a 2012 Matrix can still try to peer through the front side windows, which have remained relatively high. The same cannot be said of the side windows of the new Range Rover Evoque, which are small front and back. It is not entirely clear what this car is supposed to evoke; to CelloMom it only brings to mind the image of two gorillas dallying on the Rover's roof all night, leaving at daylight completely satisfied - in the knowledge that they have ruined a perfectly good car. The Evoque resembles nothing so much as that medieval helmet with the slits. What are its owners so afraid of?

November 30, 2011

Review: Nissan Murano

Crossing over into new territory, CelloMom considers the Nissan Murano, a crossover utility vehicle, or CUV. Had to look up what the term means, exactly: a CUV is built on a passenger car platform but borrows elements from SUVs, hatchbacks and station wagons.

The Murano comes in rather a sweet and well-proportioned package, as viewed from the side, and as long as one is careful not to look at it head on; following the current trend the front of the car presents a grim face which is called "agressive" with a measure of admiration which is baffling to CelloMom.

True to its name, there is plenty of glass on this car: the windows of the back row remain reasonably large, which is nice for the denizens of the back row who tend to be short people. And you can optionally get a moonroof which unfortunately comes in two parts, one sliver over the front seats and another sliver over the back seats. Even if the bar in between is necessary for structural strength, it does mean that the moonroof is less than breathtaking.

Of course, you don't need the moonroof for backseat navigating, since the Murano comes with a navigator built into the dashboard. The other cool thing on the dashboard is the ON button, which is all you need to get the car started, just like in the old-fashioned Jaguars. No need to ever get your car keys out of your pocket, even for getting into the car. Nice for those times that you have a toddler and groceries in your arms and it's raining and you really don't want to be fishing around for your keys.

There is more than enough space in the back for a cello, and the total cargo space can be enlarged to a nice 64cuft with the back row folded down to make a flat floor, at the height of the opening of the hatch. There is plenty of legspace for tall people even when seated in the back.

But this is one heavy-boned car, weighing in at 1742kg (3841 lbs), a lot more than the weight of a nearly-full-size car like the Honda Accord, "only" 1487kg (3279 lbs). It's not just from its over-sized 3.5L V6 engine: even the Japanese version with the 2.5L 4-cylinder engine still weighs 1650kg (3637 lbs). You wonder where all that weight goes.

Nissan does not offer the Murano for sale in the UK. In the Netherlands, you can only buy the 3.5L version, and MRSP starts from € 69,350 (US $ 93,200): it falls in the "F" category for CO2 emissions, so it got hit by the gas-guzzler tax. Cars in general, and certainly SUVs, are really cheap in the US.

Bottom line for CelloMom: Nice car, cool tech, lots of room. But we're past 20mpg now. Even the smaller 2.5L engine only gets around 25mpg (and that's being generous: the Japanese 10.15 standard tends to gross overstatement of fuel efficiency) . Not for this century.


Nissan Murano, Same-Model comparison, different engine.

US Japan
Type S FWD 250XL 2WD
Year 2012 2012
Emissions rating ULEV  
MSRP $ 29,290 ¥ 2,971,500
CelloMom Rating
Fuel Economy:
City/Hwy quoted 18 / 24  
Avg. quoted 20 mpg 11.6km/L (27mpg)
(10.15 schedule).
Avg. actual   between 22-25mpg

V6 24-vlv

2.5L 4-cyl.
Power 260 HP @ 6000rpm 170PS @ 5600rpm
Gears Xtronic CVT (auto) Xtronic CVT (auto)
Fuel Unleaded Regular Gasoline
Length, mm(in) 189.9in 4845mm
Width, mm(in) 74.1in 1885mm
Height, mm(in) 67.0in 1700mm
Weight, kg(lbs) 3841 lbs(1742kg) 1650 kg (3637 lbs)
Trunk volume, liters(cuft) 31.6 / 64 cuft  
Turning radius, m(ft)   11.4m
Top speed, kph(mph)    

November 25, 2011

VW Bulli is a turkey

You know CelloMom loves Volkswagens. But it was with dismay that she first greeted the new VW concept microbus, nicknamed the Bulli. Allright, it was actually a viscreal reaction: "Eeuw!". The Bulli gets CelloMom's 2011 Turkey Award.

The new 2012 Beetle was actually a runner-up, but someone has already stomped on that one so it now looks like a squashed bug, saving CelloMom the trouble. But the more she heard about this Bulli thing, the more it started to look like a Christmas tree festooned with glittering gimmicks.

First gimmick: it was designed, and even painted, to remind of the very successful VW Type 2, variously known as the VW bus, the camper, the hippiemobile, etc. Tug the heartstrings, cue the violins - I mean the Grateful Dead.

You might argue that the T1 was ugly; but it was ugly with character. It invariably invokes an "AawwWW!" from CelloMom's chidren whenever we spot one on the road. Besides, you learned to love its homeliness for all the good times you had travelling in it. Even when it did break down you could repair it in the comfort of its shelter. CelloMom is not tall and appreciated the T2 because she could swing the kitchen out of the way, remove the engine cover, sit over the engine and really reach in, even using leg strength for tightening the fan belt. Try that with a front-engine model.

If the Type 2 was called a microbus, the Bulli should be classified a nanobus. It is not long, about the length of a Honda Fit. It is said to carry six, because its body is quite wide. But still, behind that protruding engine in the stubby nose, and two rows of seats, there is barely room in the very back for one cello. Perhaps a guitar and a small amp. Forget about camping gear.

So it's wide, short and boxy on the back. Only a piece of plywood with the same frontal area has more air resistance. Even a turkey (with its tail down) has better aerodynamic design.

The model rolled out at the various auto shows this year was fitted with an electric engine: another gimmick playing to the current infatuation with EVs.

And that iPad installed on the dashboard! CelloMom has nothing against iPads - except when they live on car consoles. Can you just see the roadside scene, police cruiser's lights flashing: "OK, driver's license. Right. Say, officer, can you hang on one minute? I'm on this online game and I just need 5 more points to get to the next level."

Let's hope the Bulli will never see the production line. What's wrong with the VW Sharan? Except for its utter unavailability in the US.

November 23, 2011

Review Update: Volkswagen Passat

It's starting. After years of steadily nudging up engine volumes, inevitably with decreasing fuel efficiency, Volkswagen has bucked the trend with the introduction of the 2012 Volkswagen Passat 2.0L TDI. 31 / 43 mpg (cty/hwy), 140HP, more than enough power to navigate the nation's highways.

Despite grumbling about the CAFE2025 standards, because those are more than indulgent in the small trucks & SUV sector, apparently Volkswagen has moved to comply anyway, by starting to offer more fuel-efficient models in the US. It's the easy way. It's about time. And they didn't even go all the way.

The Passat Bluemotion 2.0L TDI still gets higher mileage, 48mpg in real-life use. This is the one that in Germany is called the "BlueTDI". It comes with a few extra fuel-saving technologies, such as a Start-Stop function that turns off the engine instead of allowing you to idle.

Moving another step ahead, but in European markets only, VW has introduced the "New Bluemotion Passat". This one comes with a 1.6L TDI engine. Its 105HP is plenty of power for the flat terrain of northern Germany (as well as for large swaths of the US, such as the midwestern plains). While its claimed mileage of 4.1L/100km (57mpg) is overstated, it will do better than the 2.0L version's 48mpg.

Best of all, the price on the New Bluemotion 1.6L TDI is €3,000 lower than that of the 2.0L BlueTDI, for equal trim. What's not to love? It will come to the US - eventually: a few years from now, when the CAFE2025 fuel efficiency requirements really start to squeeze.

November 22, 2011

Where are the women writing about cars?

Vive la différence! Of course women are different from men. It is said often enough that they are tribes from two different planets. So of course their choice of cars, and their motivations for that choice, are not the same. Then why is it so difficult to find women among the legions of car reviewers?

This post was written for BlogHer; read the rest here.

November 18, 2011

Men buy throbbing engines, women buy gas sippers with style and safety

The movie "Cars" is packed with vehicular stereotypes, from the rusty but trusty country truck, to the VW minivan peddling gas ("I got organic fuel, man!") to the heroine and enabler (the character whose actions make it possible for the hero to achieve his resolution).

The heroine, a light blue Porsche 911, is an icon. Everybody recognises it, its curves are irresistible, and male cars are supposed to go gaga over it.

In real life also, it is overwhelmingly men who fall in love with and buy the Porsche 911. A study released this spring by Truecar, the car sales specialists, is as crowded with stereotypes as "Cars" the movie.

Truecar collected data on more than eight million vehicle purchases in the US in 2010, and for each make and model tallied the percentage registered to men and to women. Among manufacturers, women favour Minis; Ferrari's sales go to men by a huge margin. The top ten brands favoured by women give, on average, a higher discount from the MSRP than the top ten favoured by men. CelloMom supposes that when you're buying a Maserati or a Jaguar it looks less than dignified to be niggling on the price.

The Truecar study lists the ten car models most favoured by men, that is, with the highest percentage of males registering the car. In the table below, CelloMom has added the columns characterising the cars.


Top male purchases in 2010

Make / Model %
Porsche 911 87.9 3.4L 18/25 350 82,100
Chevrolet Corvette 86.7 6.2L 16/26 430 49,525
BMW M3 85.6 4.0L 14/20 414 55,900
Audi S5 83.0 4.2L 14/22 354 53,900
Average peacock feather   4.5L 16/23 387 60,356
GMC Sierra 87.4 4.3L 15/20 195 21,945
Chevrolet Silverado 86.3 4.3L 14/18 195 21,945
Ford F-150 86.3 3.7L 17/23 302 22,990
Ford Ranger 84.4 2.3L 22/27 143 18,160
Toyota Tundra 84.3 3.0L 16/20 270 27,115
Dodge Ram 84.2 3.7L 14/20 210 21,475
Average practical truck   3.6L 16/21 219 22,272

CelloMom has taken the liberty of scrambling the order, to group the cars in two categories: practical and otherwise. The first four cars fall in the latter category: they are all display devices, and we're not talking computer screens. Men are just programmed to display their prowess like peacocks, stags and stallions. In the old days, they would go for the chariot with four barely-in-control stallions. Now, in the industrialised west, they go for four-wheeled vehicles propelled by engines with the power of 400 horses. Never mind that on the streets of Manhattan or on the congested LA freeways you never get to use all that horsepower, just like in the crowded streets of ancient Rome a team of fiery Arabian stallions was more a liability than a pleasure ride.

The point is, these cars exude an aura of power and prestige, and the bank account that goes with that. Either that, or a desire to project an aura of power and prestige, even if it comes with an oversized car loan that you have to pull like the peacock dragging its tail wherever it goes. You can't deny it's a show-stopping animal, though. The peacock that is. Oh allright, CelloMom herself does have a soft spot for the 911. Pity it just won't do for the family. Not to mention the cello. The budget? - you don't think about budget when you think of the 911.

*Sigh*. Moving right along. The second group of cars in the table above are not cars, but trucks. (Isn't it interesting how it's okay to call an Odyssey a "mini-van", but it's out of bounds to call a Tundra a "mini-truck"? After all, these are not your Mack 18-wheelers). Many of their drivers buy these trucks from a strictly utilitarian point of view; think of construction workers who have to haul large and heavy things regularly.

One example is CelloMom's friend Jonathan, an imaginative stone sculptor who prefers to work with upcycled material. Once he hauled five huge chunks of granite salvaged from an old stone bridge that was being replaced by a steel one; together these must have weighed close to 7500lbs. For that kind of load you need something like a Chevy 3500; Jonathan's has a double set of wheels at the back, and an immense turbo-charged engine that runs on diesel. When he starts it up the whole neighbourhood knows it.

Another truck-driving example is CelloMom's friend Chris, who owns a 17-horse barn that she runs largely by herself. She drives a Ford F150 for hauling hay bales, fences and such, and to hitch the horse trailer to when she takes students to a show. But CelloMom knows she's been eyeing a used VW Beetle to use as a city car, for the manoeuverability and the better fuel efficiency.

Funny that, about the Beetle. It happens to be the car with the highest percentage of women buyers, 60.6%. In the table below CelloMom has again re-arranged the order of the list, to sort the cars into two groups.

You might not think that the 52-55% in the list is an overwhelmingly large female percentage, but you need to keep in mind that in the Truecar study, women account for 34% of the car registrations overall. Yet a University of Pennsylvania study has found that in the US, about equal numbers of men and women hold a driver's licence. Probably part of the difference is because in many families a car might be registered to the husband even though it's used primarily by the wife. So take the percentages in the table below with a grain of salt.


Top female purchases in 2010

Make / Model %
VW New Beetle 60.6 2.5L 22/31 170 19,795
VW Eos 55.3 2.0L 22/29 200 33,995
Volvo S40 54.5 2.4L 21/30 168 26,200
Nissan Sentra 53.5 2.0L 27/34 140 16,060
Toyota Yaris 52.7 1.5L 30/38 106 14,115
Average stylish sipper   2.1L 24/32 157 22,033
Nissan Rogue 56.3 2.5L 23/28 170 21,530
Jeep Compass 54.3 2.0L 23/29 158 19,295
Honda CR-V 53.8 2.4L 21/28 180 21,895
Hyundai Tucson 53.2 2.0L 23/31 165 19,045
Toyota RAV4 52.7 2.5L 22/28 179 22,475
Average shining armor   2.3L 22/29 170 20,848

The cars in the upper half of the Women's table have a mix of style, fuel efficiency, and safety in varying proportions. This is a set of good-looking cars, and it's probably safe to say that the Beetle is a design icon. All the cars have decent mileage - and CelloMom's guess is that, if the smaller-engined versions were available in the US, many American women would buy them, since women's car purchases are influenced by the issue of fuel efficiency.

However, CelloMom has heard many moms say that they would love to buy a gas sipper but that those make them feel less safe on the road, which they have to share with heavier vehicles like those in the Men's list, above.

The safety issue is part of the reason why SUVs and cross-overs, like those in the bottom half of the Women's table, feature so prominently in women's choice. SUVs tend to be heavier than sedans and hatchbacks, and you sit higher, which gives you a leg up on those ridiculously high SUV bumpers, and a better view of who might be inclined to bump their manly truck (or larger SUV) into the vehicle in which you're ferrying your children. Although chivalry is far from dead, there sure is a dearth of it on the road. So, if the knights around you are just interested in their own chargers, perhaps the best you can do is to surround yourself in your own shining armour.

From the Women's list it's clear that horsepower is not a women's preoccupation: apart from the VW Eos, all the cars in the Women's table have less power than those in the Men's table. In order to make a fair comparison, for each model CelloMom has chosen the engine with the smallest power, the one that tends to have the lowest price tag as well.

On the whole, things are not as black and white as suggested by the catchy titles of the articles covering this study. The study itself it titled "Men go for looks; women opt for practicality"; but CelloMom would say both men and women go for looks or practicality, each in their own way. The folks at CarFinder advanced the title "Men like trucks and chicks dig VW". Okay: sure grabs your attention.

So here is CelloMom's gambit for a catchy title that ignores the nuances revealed by the Truecar study, with a nod to the town that houses Volkswagen's headquarters: "Men are from Mars, women are from Wolfsburg, Germany".

November 14, 2011

Hand my car keys to a 16-year old? No, thanks.

It appears CelloMom's eldest bucks the trend of teens who are not burning to get that driver's licence the moment they turn 16. The local high school offers driver's ed for sophomores, and Eldest at some level really believes that, at sixteen, CelloMom will release the family car to carry a bunch of teens to Arizona. For cactus watching. (We all need our dreams, right? And hey - among things that could attract teenagers, cacti would rank very high in CelloMom's list of preferences).

CelloDad keeps pointing out that he was a young 32 when he first got his driver's license, and there is no reason why his children should be any younger. But CelloDad is being disingenious: he lived in the Netherlands, and got around on his bike and trains and buses, occasionally getting rides with friends who did brave, and pass, the murderous driver's test.

Teens and cars are a dangerous combination. The mortality rates in traffic accidents is a few times higher for teens than for the population average. Once, a long time ago, CelloMom herself nearly died in a car driven by a teenager. On a road trip.

So no, we're not ready to relinquish the keys to the car, thank you very much. Not until they pass the in-house road test, administered by CelloMom, which will be much more strict than the Dutch one. CelloMom looks with amazement at sites where people discuss wrenching questions like "What is a good teen car?" Euhh: a bike? For getting around town, that will have to do; for young legs it should be no problem. Later on in college? We'll have enough on our plate dealing with the tuition. Later later for the first job? That's our children's problem, not ours. Hopefully they will be sensible enough to save up for a used car rather than get an expensive car loan for a shiny new one.

Meanwhile, we are happy to supply the rides, to wherever. The library when it's pouring. The mall. Even the local nursery, to supplement the growing collection of cacti.

November 11, 2011

How much horsepower do you need?

One very important item in the "Performance Specification" page of any car is the power of the engine. CelloMom explores what exactly you need all that horsepower for, and how much is enough.

Let's put the conclusion right here: 76HP is enough to cruise the nation's interstate highway system at 65 mph in a large family sedan (except in high winds). Read on for details, and to check my math.

To tell the truth, a single horse can be hitched to a car and move it forward. Heck, even a scrawny child like CelloPlayer could push a car. CelloMom herself has done it often enough, to help her dad start the car when the battery has run down. CelloMom's dad believed that jumper cables were for helping other people jumpstart their car.

Of course, a child-pushed car will only go as fast as the child can run. Same for the one-horse car. But even an infinitely swift horse will not be able to pull a car faster than some maximum speed. It's because of air resistance, which you can feel as in your face when you bike at decently high speeds.


Aerodynamic resistance.

Inside most cars you don't feel the wind, but the air resistance is there nonetheless, and it is the larger because the car has a larger area facing that wind than you and your bike together. The power required to match the air resistance, or drag, is:

Pair = ½ Cd A ρ v3

An equation is worth at least a thousand words! This one is pretty straightforward, let's look at its parts:

Cd is the drag coefficient (that is, a fudge factor, that depends on the shape of the car)
A is the frontal area of the car
ρ = 1.20 kg/m3 is the density of air
v is the speed of the car.

If you look at the equation above, at standstill (v=0), there is no air resistance. But once you're moving the power rises rapidly, as the speed cubed. This means that in order to go 50mph on a country road, your engine has to put out 8 times the power it does as when puttering around town at 25mpg, just to deal with the drag.

The larger the car, the larger the frontal area A, and the larger the drag. For a truck, A is seriously larger than for a Mini.

A truck's drag coefficient is also large, close to Cd=0.6 or more, because a truck is basically box-shaped. Cars try to resemble a bullet in their outline, or better yet, a fish, in order to minimise the drag coefficient while still harbouring a decent space inside. For many passenger cars, Cd~0.3.

Finally the density of air is quite small, so you don't feel the resistance until speeds get fairly high. A medium like water has a much higher density, ρ= 1000 kg/m3, so the resistance is that much higher, as we all know when we try to walk in a swimming pool.

We're ready to try out some numbers. In the following, we'll consider the "vanilla" largish car, one that weighs 4000 lbs with a full load of a few passengers and luggage, or about 2000 kg. This car is 2m wide and 1.5m tall (think of a Toyota Camry or a Honda Accord). Oh, and CelloMom does everything in metric, because that way all the equations are simple. The only concession is that in the end we will convert Watts (W) to Horsepower (HP): 1HP = 746W. Sigh.

Let's take the vanilla car out on a highway cruise, at 65 mph or 30m/s. At that speed, Pair = 14.6 kW = 19.5HP. Speeding at 80 mph takes nearly twice as much power: Pair = 36HP. Think of that next time your right foot becomes heavy.

Once on a camping trip in a 1985 VW van that belonged to CelloMom's dad, we met a hurricane. The wind was coming in straight at the windshield, but we had a ferry to catch so we kept going on that highway. The VW's frontal area was large because of its height; its boxy shape gave a large drag coefficient; it had a 1.8L boxer-type engine. All in all, we could go no faster than 60 mph, even with the accelerator pedal pushed all the way down. But considering the wind was in our faces, the effective total wind speed was probably close to 100mph. (Arrived at the shore, we found that the ferry was closed down for the day).


Rolling resistance.

Let's slow down a bit and get off the highway to mull things over. As you slow to pedestrian speeds the air drag is very small, but coasting in neutral your car will eventually come to a stop. That's because of friction on the car's tires, which deform elastically so you don't have to feel every pebble and pothole on the road. The power to overcome the rolling resistance is:

Prr = Crr mgv

Here v is the speed of the car,
g is the specific gravity, g=10 m/s2
m is the weight of the car
Crr is the coefficient of rolling resistance, another fudge factor.

Crr depends on the size of the wheel and the material of the tire and the road surface. If you've ever chased a marble or a ball bearing down the pavement you know that hard round things have a small Crr: they can keep going forever. Try it with a steel ball bearing in a steel mixing bowl from the kitchen (Crr less than 0.001). Carriage wheels were made of wood with a band of iron on the outside: that made it easy for the horse who had to pull the carriage - but the noise! And the passengers tended to get their teeth rattled inside their heads. The rubber on a car's tire takes away that nasty effect by absorbing the impact of road roughness, but that means the rolling resistance is also larger, Crr = 0.01 for most car tires.

Prr also increases with the weight of the car because after all, it's gravity that does the job of mushing the tires onto the road surface.

For our vanilla car going at 65 mph, Prr = 6 kW = 8HP, or about 40% of Pair. This is one reason why fuel-efficient cars tend to be lighter: decreasing m also decreases Prr.

But still: if you stick to the speed limit, you never need more than 28HP to move your family sedan on an interstate road trip. On flat interstate highways, that is. But this country is not flat everywhere, thank goodness. Its hills and mountains are as much part of its beauty as its vast plains.


Life on a slope

There are uncounted hilltops from which you can enjoy the view; but to get to the top, you have to drive up that slope. Now your engine is not only dealing with air drag and rolling resistance, it also needs to hoist your car and its contents up the slope, against gravity. The power required to do that is

Pg = mgv sinα

As before, m is the total weight of the car
g is the specific gravity
v is the car's speed
α is the angle the road surface makes with the horizontal.

It makes sense that Pg increases with m, the car's weight, and that it is zero when the road is horizontal, that is α = 0.

But notice that Pg increases with v! That is to say, in the absense of rolling resistance, you can get up that hill even with a puny power; it just takes longer. This is why loaded trucks slow down on uphill stretches of road.

Not all of us have all day, so one of the specifications for the construction of US interstate highways is that the grade must be 6% or less, that is, for every 100 yards travelled horizontally, the vertical rise is 6 yards or less. To a good approximation, sinα < 0.06.

So heading for a hilltop at 65mph on an interstate, the engine is asked to put out at most 36 kW = 48 HP to deal with the rising altitude. If you include the 20HP for the air resistance and 8 HP for the rolling resistance, you arrive at a Grand Total of 76HP. 76HP is enough to cruise the nation's interstate highway system at 65 mph. If you are generous with yourself you can double that and put a 150HP engine in, which lets you live a little, and go 80mph on most interstates with a fully loaded car. It also helps in very windy conditions, like a hurricane.

Who needs 250HP, even 350HP in a family sedan?
Germans on the Autobahn, that's who. Once, after a business visit to a company in the south of Germany, CelloMom was kindly offered a ride to the airport by her host, a German named Klaus, who drove a Mercedes station wagon. We were calmly talking business, until CelloMom glanced at the meters and realised we were going 200kph or nearly 125 mph. It was a quiet stretch of German Autobahn at a quiet time of day, but passing trucks who were only going 110kph or so, just a few feet away in the next lane, was a little nervewracking. At the airport, CelloMom thanked Klaus politely but climbed out of his car slightly shaken, resolving to take the train next time.

At Klaus' cruising speed of 200kph, or nearly 60 m/s, Pair = 160HP and Prr = 16HP. If the uphill slope on that Autobahn was at most 6%, it would require an additional Pg = 96HP from the engine. So Klaus would need an engine with at least 272HP, and 350HP would not be too much. If he habitually drives faster, he might need more horsepower in his engine. But we're talking white-knuckle speeds over 125 mph.

There is one other reason to have huge amounts of power under the hood, a reason beloved of jackrabbits and their close relation, the average human male everywhere.



Ah, sweet acceleration! That feeling that you're going somewhere. One of the specs prominently featured, especially for cars at the high end of the power spectrum, is how long it takes to accelerate the car from 0 to 60mph. For any self-respecting muscle car, this time is quite a bit less than 10 seconds. Let's see what that means for the power requirement.

The energy of a car travelling at a speed v is E = ½ mv2 (with m the mass of the car, also known as weight). Our 2000 kg car going 60mph would have an energy of E = 719 kJoules. The power to accelerate this car to 60mph in time t is P= E/t, or the other way around, t = E/P. This tells you what you already knew: the larger the power, the shorter the acceleration time. At 100HP (75kW), t = 9.6 seconds. At 400HP, the time is shortened to t = 2.4 seconds.

At accelerations like that, you can use your car to hug your friends: you merely put down your foot on the accelerator, and your friends are pressed into the passenger seat. You can get away from the traffic light ahead of anybody else - this is really what it's all about, right guys? You can jump into highway traffic without having to wait for the safe gap between cars. You can cause the groceries to rattle around in the trunk and the eggs to slide and go splat against the rear wall. You can wreak havoc on cellos and other delicate musical instruments.

CelloMom can live without all this sound and fury. CelloMom needs her eggs to come home whole, and needs to protect the rented cello. And CelloMom has learned (the hard way, it should be said) that leaving on time beats driving like a jackrabbit by a long shot, preventing wear and tear both on the car and on the nerves.

And CelloPlayer would ask, who needs 350 horses? All you need is one horse. Add a saddle, you're set to go.



You may also like:
1. What's so clean about diesel?
2. Why the new CAFE standard is just my cup of tea
3. How to buy a gas sipper for less
4. Have your Cake and Drive it Too: of Fuel Economy, Performance, and Moms


November 4, 2011

Why are cars so small outside the US?

A science fiction story once reflected that the planetary diaspora of human vehicles still basically followed the size standards set by the Romans when they built Europe's first interstate highway system. This is true of NASA's Mars rover "Curiosity" which is to be launched later this month.

It is true of earth-bound passenger cars built today, most of which would have no trouble fitting in the grooves worn by Roman ox carts and war chariots, such as the ones found on the stone-paved streets of Pompeii.

The legacy is inescapable, even for Americans who are said to like everything big: houses, TV screens, softdrinks cups - and cars. American cars grew steadily larger until they became the behemoths of the early 70s. After the oil crisis, they suddenly became smaller, but over the decades since then they have put on volume and weight again, while elsewhere in the world cars have stayed relatively small.

Many governments responded to the 1973 energy crisis by embarking on a policy of energy conservation, which has led to innovations in the manufacture of gas-frugal engines, and the marketing of smaller and lighter cars. The US has chosen a different path toward its energy security - but CelloMom will refrain from hyperventilating about that.

In the 80s and 90s, Detroit, feeling the heat of Japanese competition, asked for and got limits on car imports into the US. Foreign carmakers responded by importing only their largest models which have the highest margin. It is still that way today: for instance, Toyota has a whole line of tiny cars that are never seen here (in this context, Yaris is not tiny).

Another part of the explanation lies in American geography: the country is simply enormous, and there's plenty of space to spread out. Compare this to the old country, whose cities have grown around a nucleus founded in the middle ages, where the old Roman roads set the scale for the expanding construction. In Asia, the oldest streets are even narrower.

In Europe, high population density and a good public transport network are further reasons that not much space is given to car traffic. Many cities have been re-designed to keep cars out as much as possible. Anyway, who wants to be in a Dodge Caravan negotiating streets that were designed for light horse-drawn carriages? And where would you park the thing?

About parking.

In many places in Japan, the purchase of a car requires not only the financing, but also proof that you have a parking space for your future conveyance. There is a good reason for this rule: Even outside congested Tokyo, space is at a premium. CelloMom once spotted a minivan parked in a carport outside of Kochi. Its right-hand outside mirror had been folded in, and was virtually touching the carport wall. On the left (driver) side, there was about 8 inches of space. Either that driver was really skinny, or s/he climbed out through the rear hatch.

In the Dutch neighbourhood where CelloMom grew up there is no space for carports, just roadside parking. You couldn't park a Prius there. Well, you could, but the neighbouring spot had better contain a smaller car. Come to think of it, there are a bunch of really small cars in this neighbourhood, like the Ford Ka, the Peugeot 107 and the Toyota Aygo, the ones that fit very well in those parking spaces.

CelloPlayer went out with a measuring tape and found that those parking spots were just 84" x 176" (that's 7' x 14'8" and that IS a bit small; in most of Europe, a parking spot is around 8' x 16'). Once back in the US, we went out to measure the parking spots at those newer malls with the mega-stores: those spots are 9' x 18'.

The picture above shows three adjacent parking spots in CelloMom's old neighbourhood, and one parking spot at a US mall, all outlined in yellow dashed lines. Where a Honda Fit would "fit" just fine (left-most car in the picture) in the tiny spaces, a Dodge Caravan would spill over on all four sides (middle car in picture). Providing small parking spaces is just another way to apply pressure to keep gas guzzlers out of residential neighbourhoods. That same Caravan fits comfortably at a US shopping mall (rightmost car).

Even so, we've come a long, long way: the Caravan is dwarfed by some of the cars that used to be the US norm. One example is the Buick LeSabre: fully two feet longer than the contemporary minivan, it would stick way out among a row of Siennas and Odysseys and such. When the LeSabre first came out in 1959, you could only buy it with a 6.0L V8 engine that puts out 250HP. In the early 1970s one of the options was a 7.5L V8 engine. After that the engines got smaller and smaller, bucking the trend for many other models, until the last LeSabre was delivered in 2005 with a 3.8L V6 engine - but one that still delivered 205HP.
Take heart: engine efficiency has come a long way as well.

Responding to relentless pressure from governments that do subscribe to the Kyoto protocol, many car manufacturers outside the US have developed smaller, more frugal engines that still pack a punch: for instance, 211HP is what's delivered by the 2.0L TFSI gasoline engine in the Audi A4 Avant - you don't need a 3.8L V6 engine to do the job. Smaller engines are pushing fuel efficiencies well past 50mpg, even without hybrid technology, keeping down the purchase cost. For the short to medium term, CelloMom would put her money on those, rather than on the yet-to-be-developed but already expensive electric cars US carmakers like to push.

November 2, 2011

Review: Citroën C4 Picasso / Grand Picasso

Here is a moderately sized MPV with plenty of space, a panoramic view, and outfitted with a range of engines that get up to 42mpg in real life: what's not to love?

Visit the Citroën website: here is a place that is decidedly different from most auto websites in the US. The feel of it is just different. Once your stunned eyes have adjusted to its aesthetic, hover your mouse over the menu item that says "Véhicules" and find the C4 Picasso. Among the current fleet of cars that sink into vanilla anonymity in their drive to resemble one another, this is a car that is distinctive! You can spot it a mile away.

Those who make snide remarks about how Toyota Prius resembles an egg have never seen the Citroën Picasso. Before they put on that overhang in the back, the Picasso really looked like an egg. But don't snicker before you've actually had a chance to climb into one: the panoramic windows, which continue on the roof (!), are a revelation.

Two summers ago, CelloMom decided to take the children on a camping trip in France. CelloDad, who likes the room service kind of holiday, stayed behind, but grandpa, who adores camping, came along. It was a last-minute thing, so CelloMom went to the car rental in Holland and asked for something that would fit four people plus camping gear. What she got was the slightly larger version of the Picasso, the Citroën C4 Grand Picasso, longer by nearly 9 inches and taller at the back, and not nearly so egg-like in shape (pity). There was an optional third row of seats but we kept that folded down to make space for the gear.

The windscreen is enormous. As you sit behind the wheel, its top edge is out of your field of view. The side windows continue to the very front corners, so you get the feeling of driving in a bubble.

The children loved the big windows in the back. Too many cars have rears which are squished for the sake of aerodynamics, and the windows in the back row really suffer from it. Not so in the Picasso: the windows, even in the back, start low enough that a child can look out without that nose-on-the-glass trick. And they go up. Way up. And continue on the roof. That roof window really bailed us out on more than one occasion, because the children were able to see the road signs and provided excellent navigation services from the back seat while grandpa, who had forgotten to bring his reading glasses, was still squinting at his map.

At 4.59 metre length (181 in) this was not your lumbering US-style MPV: parking in old French towns with narrow stone-paved streets was no problem. But inside, there was plenty of space to be comfortable for long drives. We traveled west through Normandy and Bretagne, eating like sultans between the fossil hunting, church viewing and beach visits. At most campsites, the check-in routine included putting in an order for baguettes and croissants which would arrive the next morning, fresh from the local bakery and still warm. A civilised way to camp!

CelloMom and the children would retire in the tent, and grandpa would install himself in the car: you can fold down the second row of chairs to make a cavernous flat-floor place to spread out a sleeping bag, and watch the stars in warmth and comfiness.

The rental Grand Picasso came with an automatic transmission. While CelloMom usually prefers a manual transmission, in this case the clever EGS (Electronic Gearbox System) actually delivered slightly better fuel economy than the manual transmission (see table below), partly because the automatic version has a turbo-booster. The gasoline version gets an official fuel efficiency of 6.9 L/100km (34 mpg) for the manual version, and 6.7 L/100km (35 mpg) for the automatic. The latter's 156HP was more than enough to negotiate the hilly country in Bretagne with a full load. The similarly-sized diesel engine gets 48 mpg officially, 42mpg in real life.

So then: seats for up to 7 passengers, amazing view, space for grandpa to stretch out (never mind the cello), 42mpg - What's not to love? Well, unlike the Opel Meriva, the Grand Picasso doesn't have a built-in bicycle carrier. Then again, it has a roof-length rail ready to receive a bike rack. CelloMom went to a Peugeot dealer and sat in a Peugeot 5008, which shares the Picasso's platform, and was impressed by the way you can keep an eye on your bike even as you're zipping along the highway. (The demo bike in the photo is, of course, a Peugeot). Allright, then, perhaps one doesn't need a built-in bike rack.

In the UK, the brand is pronounced "citron", even though the name in French has three syllables. Without the umlaut on the e, you get the Dutch word for "lemon". Perhaps it is the unfortunate name that has kept this brand mostly inside Europe. But make no mistake: the Grand Picasso is no lemon. It is, on the contrary, a highly desirable family car, versatile, fun to drive, and best of all: gas-frugal.


Citroën C4 Grand Picasso HDI-110, auto vs. manual

Trim C4 Tendance C4 Tendance
Type EGS Auto HDI 110
Year 2012 2012
Emissions rating Euro5 "B" Euro5 "B"
MSRP € 20,905 pre-tax
($ 28,700)
€ 19,883 pre-tax
($ 27,300)
CelloMom Rating
Fuel Economy:
City/Hwy quoted 5.4 / 4.6 L/100km 6.5 / 4.6 L/100km
Avg. quoted 4.9 L/100km
(48 mpg)
5.3 L/100km
(44 mpg)
Avg. actual 50.1 mpg_imp
(42 MPG)
48.5 mpg_imp
(40 MPG)

1.6L EGS stop&start

1.6L HDI
Power 112 HP @ 3600rpm 112 HP @ 3600 rpm
Gears 6-spd auto 6-spd manual
Fuel Diesel Diesel
Length, mm(in) 4590 mm (180.7 in)  
Width, mm(in) 1830 mm (72.0 in)  
Height, mm(in) 1710 mm (67.3 in)  
Weight, kg(lbs) 1495 kg (3296 lbs)  
Trunk volume, liters(cuft) 576L (1951L w 2nd
row seats down)
Turning radius, m(ft)    
Top speed, kph(mph) 182 kph (113 mph) 181 kph (112 mph)

October 29, 2011

LifeCycle Energy Analysis for YOUR car

Time to step away from the "vanilla" car and estimate the total energy used to manufacture and drive a particular car over its lifetime.

The GREET model developed at Argonne National Lab considers how much energy it takes to manufacture the "average" car. We take a bold step and make the assumption that the manufacturing energy increases linearly with the weight of the car, so if my car weighs 30% more than your car, it took 30% more energy to manufacture my car than yours.

This is not an exact calculation, but will serve for a rough estimate. From the GREET model results, the energy to build a car (the "vehicle cycle") is about 30MJ per pound for a conventional car with an internal combustion engine, and about 39MJ per pound for a hybrid vehicle.

The other numbers we need to keep in mind is that there is 121MJ in a gallon of gasoline, and 138MJ in a gallon of diesel.

We're ready to do a rough comparison. The table below shows a few cars with their kerb weight, the energy to manufacture them, the real-life fuel economy, the total fuel energy for 150,000 miles, including the well-to-pump energy ("fuel cycle"), and finally, in the right-most column, the total energy consumed in making the car and driving it for all those 150,000 miles (but excluding any repairs).


Lifecycle Energy Analysis
(assuming total 150,000 miles)

Real Fuel
Toyota Prius
Toyota iQ
VW Golf TDI 1.6L
VW Golf TDI 2.0L
Honda Fit
Honda Odyssey
Audi A4 Avant 2.0 TFSI
Audi A4 Avant 2.0 TDI

For total lifecycle energy, Toyota Prius, the only hybrid model in the table, does exceedingly well, better even than tiny Toyota iQ which in Japan falls in the "2Box" category, that is, a box on wheels that fits two people. Two very good friends.

The VW Golf with the 1.6L diesel engine does only a little worse than the Prius, the one with the 2.0L engine quite a bit worse. Here is a clear example of CelloMom's idea that, carbon and dollar wise, you can have your cake and eat it too: the 1.6L Golf will be cheaper to buy, cheaper to drive, and give you the feelgood factor of significantly lower carbon emissions.

The smaller Honda Fit has nearly the same total lifecycle energy as the Golf with the larger engine; but it is significantly cheaper to buy, as well.

At 1232GJ total lifecycle energy, the Odyssey minivan consumes 2.5 times more energy than the Prius, which is not so great considering you can transport only 1.4 times as many people in the minivan. Energetically speaking the minivan is more attractive only if you have five or more passengers to move every day, e.g. if you share the school commute with friends.

The Audi A4 station wagon makes sense only for the most frugal engine: for the less frugal ones you might as well buy a minivan and get more cargo space and passenger flexiblity, foregoing the carbon feelgood factor. Here the cost equation is less clear, since the diesel version has a higher purchase price. But at a fuel economy of 39mpg for the diesel, as compared to 24mpg for the gasoline version, the frugal diesel is still cheaper overall.