"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."
So, there you have it. The practice may be controversial, but the word is here to stay. Also, in 2006, the Word of the Year was "carbon neutral" and in 2007 it was "locavore." Thanks for the tip, Rebecca!
[Source: Oxford University Press Blog]