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Toya, a 56-year-old manager for a tofu maker in central Japan, puts special tires on his Prius, tapes plastic and cardboard over the engine and blocks the grill with foam rubber. He drives without shoes and hacks into his car's computer -- all in the pursuit of maximum distance with minimum gasoline.
Toya is one of about 100 nenpimania, Japanese for ``mileage maniacs,'' or hybrid owners who compete against each other to squeeze as much as 115 miles per gallon out of their cars. In a country where gasoline costs more than $4 a gallon, at least $1 more than the U.S. price, enthusiasts tweak their cars and hone driving techniques to cut fuel bills and gain bragging rights.
``My wife thinks I've joined some strange secret society,'' Toya said in January at a nenpimania gathering in Nagoya in central Japan.
Mileage maniacs aren't alone in pushing the limits of hybrid vehicles. As U.S. automakers General Motors Corp. and Ford Motor Co. race to introduce their own models, first rolled out by Japanese companies in 1997, engineers at Toyota and Honda Motor Co. are trying to boost hybrid performance to maintain their advantage.
``With higher oil prices and tightening environmental regulations, people will focus more on hybrid technology,'' said Koji Endo, an auto analyst at Credit Suisse First Boston in Tokyo.

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