Saturday, August 19, 2006

Early results in high gas mileage with a motorcycle

A couple months ago I bought a Honda Rebel 250cc motorcycle. I'm in the middle of building an electric motorcycle, and am needing some kind of motorcycle with which to learn the art of riding motorcycles. In California we're required to have a special drivers license, which puts me back into the role of having a learners permit and occasionally going to the DMV for a driving test. But that's a story for a different time.

I've discovered something with this motorcycle which is surprising me. You can have amazingly high miles/gallon efficiency!

I've written about this before: Riding motorcycles because they're fuel efficient

I learned before that the U.S. EPA doesn't measure miles/gallon on motorcycles, but the hints I found implied that small motorcycles (like the Rebel) would get high miles/gallon efficiency. It also makes logical sense, that a small vehicle would require less energy to move it, and that a small engine on a small vehicle should get high efficiency.

In the first couple tanks I mentally calculated the miles/gallon and was astonished to see 90 miles/gallon efficiency. But I knew the numbers were small, and inaccuracies would loom large.

High miles/gallon efficiency is important because -- I'm going to drive anyway, and to drive while using less gasoline makes for great benefits such as less pollution in the environment.

Here are the numbers for the first three tanks of gas run through the motorcycle:

Odometer Gallons bought Elapsed miles Elapsed gas bought Miles/gallon
3199.1 n/a n/a n/a n/a
3325.3 1.71 126.2 1.71 73.80
3440.3 1.53 241.2 3.24 74.44
3562.2 1.70 363.1 4.94 73.50

My calculation method is to record the gallons bought, and the odometer reading at the time it was bought. This gives me an elapsed total miles ridden and gallons bought since the beginning of these measurements, at 3199.1 miles. The elapsed miles / elapsed gallons gives elapsed miles/gallon efficiency.

Assuming the odometer is accurate.

As you can see, the efficiency is staying just above 70 miles/gallon. Take that hybrids!