Sunday, March 16, 2008

Life is a Highway... Part 3.5 or Something

This week I began hypermiling in my 1998 Saturn SL2. It is yet another spinoff of my interest in reducing fuel costs and finding alternative energy transportation. I decided to try it after reading an article in Reader's Digest at my mom's house last Sunday.

The results of my first try was a whopping 46.27 mpg in a car the EPA estimates at 33 mpg highway! I did this in heavy rush hour freeway traffic with frequent slow pockets, occasional stop and go, and freeway speeds.

Wayne Gerdes coined the term recently but the techniques have been used by some in the lean times of World War II and the oil crisis in the 1970s.

How does hypermiling work? It begins by understanding that the EPA (actually the manufacturer of the vehicle in most cases) runs a bunch of tests that "simulate" what the "average" driver will do in city streets and on the freeway. The tests include stops and starts and high speed driving with the AC on and off. Hypermilers throw out all of the "average" driver habits.

Hard acceleration wastes gas. Hard braking wastes gas. Driving faster than the speed limit wastes gas. Aerodynamic drag increases by the square of your velocity and as a function of your aerodynamic drag coefficient (based on shape of the car). Most cars are at their most efficient somewhere in the 45-55 mph range. Most drivers try to go at 70 or 75 these days.

You can then add in other tricks such as giving extra space to the car in front of you and coasting when everyone else starts braking. Stopping further back at a stop light on a hill so you can coast-start when the light turns green. There are all kinds of little tricks. A good resource for hypermilers is cleanmpg.com.

The cool thing about hypermiling is that you don't have to "DO" anything to your car other than treat it more gently. Your brakes and engine will last longer. And it won't take you that much longer to get there than you think. Despite driving slower, I don't really add more than about 5 or 10 minutes on a 33.5 mile trip.

Now if I only lived closer to work...

1 Comments:

Blogger Becca said...

I tried a little hypermiling a month or so ago after I read about it on Wisebread (will have to find you a link) but it drove me crazy!

But your increased fuel efficiency is cool! Maybe I'll have to give it a shot again.

Maybe that's why old people drive slow--fixed income, not a lot of money so they hypermile! Just a theory...

3:10 PM  

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