Maybe all we need to do to improve the fleet gas mileage is to install MPG gauges on cars and let good old American one-ups-man-ship have a free reign. That's certainly proven to be the case for some Honda Insight drivers.

Environmentalists have been stymied in getting real changes through Washington. Just last spring, pressured by both carmakers and auto unions, the Congress rejected a plan that would have increased average fuel efficiency to 36 mpg by 2016. (Thirty-six mpg! Ha!) But maybe for a year or two we should ask for something much simpler: that every vehicle on the road come equipped with a gauge like the one in my Honda. One that shows exactly what kind of mileage you're getting. I'm almost certain that without changing anything else in our cars, fuel efficiency would jump ten percent.