Thursday, April 4, 2013

Weight Watchers

"Simplify, and then add lightness" - Colin Chapman

Here's the thing.

What if I told you there was one thing you could do to a vehicle to enhance not only its performance, but also its mileage? No, I'm not referring to any kind of space-age engine tech or the fabled "60mpg catalytic converter" rumored through most of the 70's. I'm talking about weight reduction. In terms of a vehicle, weight is the enemy of every objective test. Don't believe me? Let's consider some Some examples.

The Audi S8 and the BMW 760Li are both large executive sport-sedans. They put up, I'm sure coincidentally, similar performance numbers, with the S8 edging out the 760 by a small margin, mostly owing to its Quattro all-wheel drive. However, that same system should, by all logical accounts, also rob fuel economy from the big super-sedan, as well as create losses to how much power is put to the ground. So from a powertrain standpoint, it's outclassed. Then how does it manage to do a 3.6 0-60 and still return 20 observed miles-per-gallon in a recent Car&Driver test? Simply put: weight. The big Audi is one of the most aluminum-intensive studies of modern automobile construction in recent years. It is over 500 lbs lighter than the BMW, and it shows.

Moreover, let's take an example of the same engine in two different applications. Going back to the Cruze I talked about earlier this week, the very same 1.4T I railed against in the Cruze is also available in the subcompact Sonic. In the same testing that drove the Cruze under 30 miles per gallon, the Sonic was able to maintain a 31 miles-per-gallon average. What's more, this was accomplished without trick grill shutters or low-rolling resistance tires, some of the tricks employed to turn the Cruze 1LT into the Cruze Eco.

Knowing all this, why don't companies build lightness into all of their cars? Well, that's a tricky question, but the obvious and biggest problem is price. Aluminum, carbon fiber, magnesium, and other lightweight materials are expensive. Although they are coming down, they are still beyond the reach of most normal econobox shoppers. Also, marketing plays a part. There is no badge for aluminum construction. You'll never see a car with "65% CarbonFiber" emblazoned on the front fender. Without those things, people will never give up their perceptions of the value that comes along with a small-displacement or a hybrid drivetrain, both of which easy to tell due to the identification usually plastered on the outside of the car.

All we can hope for is that companies will invest in these new technologies. As a matter of fact, Toyota weaved its own carbon fiber for their LF-A supercar. With any luck, that technology will trickle down to their passenger cars. I for one cant wait for our first affordable car that averages 35 miles-per-gallon and does 0-60 in 6.5 seconds, with a real engine, in all conditions.

And that, that's the thing.


  1. I am a little saddened by this post. Decades ago it was easy to get under 2000lbs in a compact car without resorting to expensive Aluminum alloys or composites. The difference between now and then is the continuously increasing safety standards.

    I am against these standards. As a consumer, they are extremely costly in terms of "greeness" in both the monetary and ecological sense. Car manufacturers should sell safe vehicles at a premium, just like how they sell performance/tech laden vehicles.

    1. I didn't include that in my article because it's something beyond the power of manufacturers. But you're right, most of the increase in weight is due to new, government-mandated safety features.