Photos: Ecomodders make fuel good to the last drop

What's the dark side of ecomodding?

"My wife is supremely embarrassed to be driving in my car now," Johnmeyer said of his Civic. "Some people, mostly the younger male crowd, laugh hysterically at it. They think it's some horrible attempt at hotrodding a car."

And how eco-friendly is using some toxic materials to reshape a car in the name of conserving fossil fuels? Johnmeyer and other ecomodders point out that they often recycle discarded materials such as corrugated plastic signs from political campaigns, duct tape, and bailing twine.

They also note that ecomodding isn't even the best way to make a car more efficient. Johnmeyer attributes most of his improved fuel economy to "hypermiling," rather than the physical alterations.

"It's like a video game," Johnmeyer said. "You're constantly playing with your gas pedal." Hypermilers drive slowly, cut the power at stoplights, and use cruise control to accelerate in tiny increments. They have their own Web-based communities, including GasSavers.org, MetroMPG.com, and CleanMPG.com. The same trend is known as "ecodriving" in Europe and "nempi mania" in Japan.

It helped that Johnmeyer added a switch that lets him kill the engine at stoplights. That conserves gas without shutting off the car, so that turn signals still work.