Sunday, March 7, 2010
Cars are a necessary evil
At some point, almost everyone in the US needs a car. You can only carry so many people on a motorcycle or a bike. For a long time I was very interested in the car shown above. It's call the Aptera and it was built with a single purpose in mind - efficiency. There are several factors that efficiency in cars but the two most important are weight and aerodynamic drag. Human powered bicycles can reach over 80 mph powered by a human with about 1/2 horsepower but cars require almost one hundred horsepower to reach equivalent speeds. Why? Because cars are much heavier and have tremendous drag. The shape of today's cars are not ideal for reducing aerodynamic drag. At 55mph, over 50% of a car's power is not used to propel it forward but to fight drag and this increases exponentially as speed increases. If you change nothing else on a car but its shape, you can dramatically improve fuel efficiency and performance. In fact, someone took a regular 1992 Civic CX and did nothing but change the shape of it to this:
Yes, its ugly but making it this ugly improved fuel efficiency from 47mpg to 95mpg. Simply amazing. The Aptera has an even more aerodynamic shape, has only 3 wheels to reduce rolling resistance and was originally set to weigh half the weight of a typical small car. Unfortunately, the company seems to have hit some snags and I'm no longer sure that they will be able to deliver a viable vehicle anymore.