Tuesday, January 19, 2010

Simplify. Then Add Lightness.

That's perhaps my favorite quote, and it comes from Colin Chapman, one of the greatest automotive engineers to have lived. In four mundane words he captured the essence of both race car and aerospace engineering; above all else, make it reliable and make it light. And it's something I wish the major car manufacturers of our time would take more seriously.


Our cars have become beasts. Power this, heated that, networked everything, and a screen for every passenger to consume entertainment until their eyes bleed. Headroom, legroom, elbow and shoulder room, acceleration, top speed, trunk space, number of seats, even wheel size have all notably increased. In 1987, the US average light-duty vehicle weighed 3220 lbs, put out 118 hp, and had a 0-60 time of 13.1 sec. Today, these figures are 4108 lbs (+27.5%), 225 hp (+90.7%), and 9.5 sec (-27.5%). Why? Because more, bigger, "better", and faster are all easy things to sell, and as GM and Chrysler have seen all too clearly of late, you can't make money if you can't sell cars.


But all of that comes at a price, namely efficiency. For all of the automotive advancement over the past couple of decades, we've actually lost ground on mileage. In 1987 the US vehicle fleet averaged 22.0 mpg, the high-water mark for modern vehicles. In 2009 we were at 21.1 mpg, a decline of 4.1% from 22 years ago, though to be fair, an increase of 5% from 11 years back. 


So what can we do? Adding lightness does something miraculous; any given car gets both faster and more efficient. Handling improves, acceleration improves, braking improves, mileage improves, it's a great thing. Except that, for a given car, adding lightness typically adds cost. This is because steel is cheap, and replacing it with Aluminum or Carbon Fiber (even if it's a lesser total mass) is usually not cost effective in the short run. But if you can lighten up the body, then you can get similar performance from a smaller engine and smaller brakes. That leads to even better efficiency, and that can mean overall lifecycle costs (fuel, maintenance, replacement parts) that more than make up for the initial increase in purchase price. This is especially so in periods of high fuel costs, such as we're experiencing now.


But step back even further for a moment, and consider the Honda Super Cub. It is the best selling powered vehicle of all time, with over 60 million of them produced in the last 50 years. the Super Cub's 49cc engine puts out slightly over 4 hp, but can propel a single rider up to 50 mph. For a motorized vehicle it is remarkably reliable, easy to maintain, and simple to repair when necessary. It achieves nearly 300 mpg in normal use, with only basic technology upgrades from it's initial design. And it remains a remarkable design, as it provides the basics of safe and reliable transportation and not a thing more. Simple, light, cheap, economical, reliable. When we make purchases according to that we need vs. what we might like to have, we can make some pretty smart choices. 

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