DamlierChrysler boasts that the just-announced Jeep Grand Cherokee CRD, which will go on sale in March, 2007, offers a 30-percent improvement in fuel economy over an equivalent gasoline engine.
The downside is that diesel engines also produce more pollution than gasoline. For that reason, states that follow California's lead on car pollution rules restrict the sale of diesel passenger vehicles.
Carmakers are working on technologies to clean up diesel exhaust.