Here's the Oxford American Dictionary's latest word of the year:
“Hypermiling” was coined in 2004 by Wayne Gerdes, who runs this web site. “Hypermiling” or “to hypermile” is to attempt to maximize gas mileage by making fuel-conserving adjustments to one’s car and one’s driving techniques. Rather than aiming for good mileage or even great mileage, hypermilers seek to push their gas tanks to the limit and achieve hypermileage, exceeding EPA ratings for miles per gallon.
A few years ago, journalist Dennis Gaffney went on a few drives with Gerdes, who can get 59 miles per gallon in a Honda Accord and 100 mpg in some cars, and ended up writing this engaging profile for Mother Jones. Some of Gerdes's trade secrets: He removes everything from the car that's heavy and not screwed down, overinflates his tires, avoids braking when possible, sometimes glides for miles at a time with the engine off, starts his truck by putting it in neutral and pushing it down the driveway, only turning on the engine when he actually needs to... Hey, it's a hobby.