[elhigh]

Hot VWs Magazine has been doing an on-again-off-again series of articles on a "Mileage Motor." They've gotten some pretty good results. One of the first things they did was increase the rotating mass.

They didn't knock themselves out trying to keep the reciprocating masses down - their stated goal being that they want to build a motor that anybody could duplicate on a reasonable budget. But they did bolt on a heavier flywheel and an extra-heavy pulley. I'm not sure what the rationale is, but the Super Beetle they bolted the engine into was delivering 22mpg before, with the Mileage Motor it's up past 36, and they're not babying it. Either the extra rotating mass is helping, or their motor is phenomenally good and the flywheel is masking some of the gains.