n. A person who attempts to maximize gas mileage by using driving techniques that conserve fuel.
Other Forms
She accelerates gently when the light turns green, and coasts down hills to save gas. On highways, she stays in the right lane and watches the big SUVs zoom past.

"When I see someone roar past me, I think, `They just used enough gas to last me a week,'" she said.

She is part of a small and extremely dedicated group of drivers around the country who call themselves "hypermilers." They almost exclusively drive hybrid vehicles, and their goal is simple: squeeze every mile they can out of each drop of gas.
—Chris Williams, “'Hypermiler' drivers try to squeeze every mile they can out of a gallon of gas,” The Associated Press, May 29, 2007
But Gerdes isn't just slow. He's deliberate. And he's the best hypermiler in the world. Hypermiling? What's that, you ask? It's the art of getting the most mileage out of every drop of gas in your tank. Gerdes never uses air-conditioning. He takes alternative routes to avoid red lights. Stepping on the brakes just wastes gas in his estimation. And he's known to tailgate 18-wheelers and let them pull him along.
—Francesca Segre, “Getting more mileage is an art form,” American Public Media, April 27, 2007
2004 (earliest)
Before this car I spent two years learning hypermiling on my 2004 HCH1.
—kenny, “Obsessed with the MPG gage?,” GreenHybrid, August 12, 2004