– Ben Martens

Miles Per Gallon

gasguageSeven years ago, I purchased a Scan Guage¬†and I still recommend that you pick one up for yourself if this stuff interests you. It taps into your car’s computer and gives you access to lots of the sensor data. I use it most for tracking exactly how much gas I’m using and what mileage I’m getting.

For most of that time, I had the display showing me lots of information about how many miles per gallon I was getting, but recently I realized that’s a little messed up. Miles per gallon is a good measurement if your route is unchangeable, but it misses the mark if you can choose a route. For example, I have two main routes to work. One is 12 miles and uses the interstate and the other takes backroads and is only 9 miles. The interstate route generally gets me better mileage (though it’s generally clogged with traffic so it’s not a huge win.)

I changed the ScanGuage to start showing me how many hundredths of a gallon of gas that I was using on each trip and I discovered realized that the shorter route almost always uses less gas even though I get fewer miles per gallon. So if my goal is to use as little gas as possible, I should actually choose the route with lower MPG. It’s sort of counterintuitive and obvious at the same time.