Lifetime Fuel Economy: 39.49 mpg

Saturday, June 7, 2008

First Fill-up

Well, I must say I'm pleased. The previous owner told me it gets around 31 mpg, and on my "control group" test, I logged 113 miles. 30 miles of it were with the a/c on, and miles were about 50/50 city/highway. 31.84 mpg is better than either of our cars, and I haven't done anything to the 'scort yet. Woohoo! I'm going to continue testing as a control group another day or two; I've got a 45 minute trip to a graduation party tonight and another equal-length trip tomorrow. I got almost all the wiring finished; first mod will be the tire pressure only, then hypermiling will begin!


King of the Road said...

I'll enjoy following this blog. In keeping with your scientific approach, do you plan to estimate uncertainty? I know that pumps at the gas station display to the nearest 0.001 gallon, I don't know if that's +/- 0.0005 gallons or what. But I think that that's irrelevant. I strongly believe that the biggest source of random error is the level to which you fill the tank.

In any case, I'm curious to see how far you carry your "scientific method." I've given this some thought in my own experimentation at

Will you state a hypothesis, run a controlled experiment, collect data, and exhibit a confidence level for rejection of the null hypothesis? If so, I anticipate you'll be racking up a lot of miles.

In case you're curious, I got to your blog from where my screen name is PA32R.

Matt said...

Thanks for the comments, and I'm glad to have you as a reader!
Thus far, I've used the same pump at the same station for all my fill-ups. I know this won't be possible forever, but it will definitely act to reduce my error. If the pump shuts off early on one tank, my mileage will display high, but on the next, mileage will moderate back down. I must admit it's really hard now not to mess with anything else while I'm collecting my control data. I have to do some coast length tests with my current tire pressure before I change it, and then I plan to run a tank with "maxinflated" tires before I start hypermiling. I also have decided I need to a test of a/c vs. no a/c at a standard temperature where it's necessary because my pregnant wife can't handle riding without it. Ahh, error has already entered!