The Bush administration is walking away from a $1.5 billion eight-year government-subsidized project to develop high-mileage gasoline-fueled vehicles.

On high-mileage vehicles, the piston seals may leak, which must be promptly corrected.

Analysts say this trend toward high-mileage vehicles would probably continue even though gas prices have started receding again.

The auto industry has said it would only produce high-mileage vehicles if they can be made for a price consumers would pay.

Sales at all the major Japanese automakers have remained relatively strong despite rising fuel prices, partly because of their reputation for building reliable high-mileage vehicles.

They say that manufacturers, which buy back rental cars, do not want high-mileage vehicles.

That is a goal shared, no doubt, by other auto makers that are also developing low-emission, high-mileage vehicles with advanced safety features.

Many people owning high-mileage vehicles are proud of the accomplishment and they all seem to have pet strategies to extend the lives of their cars.

But the tone of Detroit executives in talking about high-mileage vehicles has nonetheless been shifting in recent weeks.

So high-mileage vehicles produce few of these gases while gas-guzzlers produce a lot.