I recently wrote an article in UXmatters about how the information displays in my Prius changed my driving behavior. Seeing the miles per gallon (MPG) I was getting in real time, acted like a feedback loop, causing me to make a connection between my driving actions and how they affected my gas mileage.

Something I didn’t write about, however, was another type of feedback that you get as a Prius driver – the drivers behind you. When someone drives up behind you and tailgates, that’s feedback to go faster or get out of the way. However, that feedback conflicts with the feedback from your Prius to drive economically.

To drive economically and get good gas mileage requires a steady pace and slow acceleration. That doesn’t necessarily mean slow driving. I drive 65 to 75 miles-per-hour to work, while getting about 60 miles per gallon. But it does mean that you need to avoid quickly accelerating. So being a Prius driver sometimes puts your gas-saving goals in conflict with the drive-fast goals of other drivers. There’s a reason some drivers get annoyed by Prius drivers.

Although I always drive in the right hand or middle lanes when I’m driving economically, I’ve found that the best way to drive economically is to ride along behind someone else. If there’s no one in front of you, and another driver comes up from behind, you feel pressure to go faster. If you have another driver in front of you, you have an excuse to drive economically. It’s that guy’s fault, you’re just driving behind him at a reasonable distance. So you don’t feel the pressure to speed up.

I’ve gotten my highest MPG records from driving (at a safe distance) behind a truck that was going a steady, reasonable speed (maybe 70 MPH). That allows you to ignore the feedback from drivers behind you and pay attention to the MPG display.

Sounds like I’ve put too much thought into this gas mileage thing with my Prius. Maybe, but I save money and it’s fun.