Truckers are now being offered incentives to upgrade or retrofit their trucks for cleaner emissions.

This has several benefits: higher output, improved thermal efficiency, better fuel economy, and cleaner emissions.

The swirl was supposed to improve burning of the air-fuel mixture, thus enabling cleaner emissions, improving fuel economy, and increasing power.

Mr. Gennaro urges legislation to require more buses with cleaner emissions.

Honda also tinkered with the engine's software, to regulate the air-fuel ratio for cleaner emissions.

This approach results in better efficiency and cleaner emissions, but sacrifices some of the power density.

Officials, however, said that the plant would use proved technology to insure safe and clean emissions.

Unlike conventional gasoline cars, hybrids get better fuel economy, do well at slow speeds or idling, and have cleaner emissions.

The fuel injected motor produced cleaner emissions and offered a better balance of performance and daily-driver temperament.

The VP44 setup meant that timing and fuel could be precisely controlled, which led to cleaner emissions.