Thursday, June 29, 2006

Saving Gas

On my trip to the conference, I took care to try to go the speed limit, hearing that you can improve gas mileage by not driving faster than about 60. (I did drive 65 in 65 mph zones.) I encountered many construction zones as well (mostly 45 mph). The total trip, including breaks, took me 8 ½ hours.

On the way back, I “kept with the traffic” (meaning, I sped, but not as much as a lot of people!) In part this was because I departed from Major City and everyone drives crazy fast, and I adopted a “compromise speed” that was still faster than the speed limit but slower than the rest of the traffic but not so slow as to be a hazard. This launched me off on the trip in speedy mode, which I then mostly kept up, being eager to get home. While I disapproved of my doing so, to some extent, I did this in the spirit of an experiment. Would it save time? Would the gas mileage really decrease? Anyway, I didn’t speed that much, because my little car begins to shudder when I get into the 70-75 mph range.

So, what time did I gain? A half-hour. Not that impressive, really.

But here’s what is impressive: I averaged 43 miles per gallon on the way down, and averaged 40 miles per gallon coming back!

And I don’t even have a Yaris (which is supposed to get 41 mpg on the highway)—I have a manual transmission Corolla!

The lesson: I’ll stick to going the speed limit. It’s safer; it does save gas; and even on long trips, you don’t actually lose much time.


  1. I did the same experiment last year when the price at the pump started to spike. However, my results were much different than yours. As a daily driver and a super commuter I travel over 270 miles a day. During my month long test I traveled the speed limit to and from work - following the slower commuters. During this time I averaged, depending on weather and construction, 26 miles per gallon. The next month I drove like a New Yorker and took it up a notch. Instead of slowing with traffic I changed lanes to keep my speed. The results were obvious. The first day I made it home with a quarter of a tank of gas. The month prior I barely had enough in the tank to get me to the gas station down the street. The results of the month showed a good six miles per gallon increase and shaved anywhere from a half hour to forty minutes off of the nearly three hour commute. Two days in a row I averaged 41 miles-per-gallon. These days I contribute to mild weather with low humidity and light traffic. I found that during hot humid weather my car gets less miles-per-gallon than cooler temps. Another explanation is that I have to leave the interstate and travel on a secondary highway that is very hilly. On days where this highway is congested I find myself pushing the pedal to the floor to climb the hills. On days where this road is less congested I can lessen the amount of gas used by absorbing the hills and maintaining a greater speed.

    I'd like hearing how others are dealing and experimenting!


  2. Wow, interesting results! I've heard that another factor is how smoothly one drives. So those who drive slower but start and stop a lot would get worse gas mileage than driving more smoothly at somewhat faster speeds. Also, I suspect that each gear actually has its optimal speed for fuel-efficiency, and so the closer one sticks to this speed relative to each gear, the better the gas mileage.

    I too would be interested in hearing of more such experiments!

    One more general thought I'll share about driving: I try also to regard driving artistically, almost like a dance. I try to incorporate driving efficiently with driving gracefully. And I try to think kind and generous thoughts towards the other drivers on the road, even if they do things that alarm me. I give them the benefit of the doubt, and I try to remember that they, like me, are human beings trying to cope with their busy lives in this complex world.

    It's not always easy to maintain this kind of attitude, but I sense that it is good for me to keep trying.