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Lovins 22 (2:33)
Topic(s): Auto Industry / Car Culture
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Video Transcript

There have been two traditional concerns about making cars lighter: cost and safety. Let's take safety first. When a heavy car hits a light car, other things being equal, the light car will come off worse. This means heavy cars actually are hostile; they're mass aggressive if you might say. If you're in the heavy car, you can be safer but the folks in the lighter car you hit will be proportionately more at risk. So you're transferring risk from you to them and this ability to export your risk to somebody else drives a mass arms race in which you drive an SUV and she drives an eighteen wheeler and he drives a locomotive—this is nuts. Now a good way out of the mass arms race is to understand what Henry Ford told us: that you don't need weight for strength. If you did, your bicycle helmet would be made out of steel, not carbon fiber.

So lets start with the properties of the materials. It turns out that a good carbon composite part can absorb six to twelve times as much crash energy per pound as steel can and it also absorbs that energy more smoothly, so you can use the crush stroke or crush length up to twice as effectively. Now this shows up nicely in a SLR McLaren, which is a hand-made half million dollar carbon fiber kind of street license formula-one, very high speed car made by Mercedes and in the front corners of it there's a pair of about two foot long woven carbon fiber crush cones, each weighing 7-1/2 pounds. So all together they weigh 0.4 percent as much as the car and yet they can absorb the car's entire crash energy hitting the wall at sixty-six miles an hour because of the incredible energy absorbing capacity of these materials. Now, with such light but strong materials, you can make cars that are big, which is protective and comfortable, without also making them heavy, which is hostile and inefficient. Therefore you can save oil and lives and indeed money all at the same time.