I can't drive 32

Bill has been kicking my ass in the MPG race. He's averaging over 50 mpg almost every tank in his Prius, while I, in my newer Prius, hang around 39 mpg. Competitive person that I am, I find this rather frustrating. Recently, we had to go on a local client call together, so I drove and he coached me--at my request--on improving my gas mileage.

That very short drive convinced me that I will probably never be able to match his mpg.

Bill orients all of his driving toward improving gas mileage. He takes off slowly, coasts whenever possible, stays at speeds that are giving good mpg readings (the car shows you graphically how you're doing) even when those speeds are under the limit, and doesn't worry about how other drivers react to him. As he jokingly said to me, in what has become a catchphrase in parts of our company, "I'm saving the planet!" At one point, he urged me to stay at 32 in a 35 because I wasn't going to be on that stretch of road for long. "35 is just a number some guy put on a sign," he correctly observed. "You don't have to obey it."

Yes, I do. In fact, I have to drive four miles above that limit--and the safe maximum of nine miles above the limit on highways.

I can't drive 32.

Bill owns me in the mpg race.

There's only one sensible solution: I need a Tesla S (or a Tesla roadster, if I had the money).