The new Dodge Ram Heavy Duty's 6.7-litre Cummins engine is reckoned to be the first to meet the Environmental Protection Agency's new emission standards for vehicles in its class in all 50 states. They're not due for implementation until 2010.

“Our diesel meets the world's toughest emission standards for NOx,” says Cummins president and chief operating officer, Joe Loughrey. It uses an absorber catalyst to reduce NOx (oxides of nitrogen) by as much as 90 per cent, says the engine maker, and a filter to eliminate almost all particulate emissions.

The diesel is equipped with a cooled exhaust gas recirculation system plus a high-flow electronically controlled variable geometry turbocharger.