A new report by a diesel industry group shows Oregon and Idaho are in the top 10 when it comes to highest rates of diesel vehicle ownership in the nation.
But the overall rate pales in comparison to other parts of the world.
Northwesterners use powerful diesel pick-ups to pull boats, RV's and farm equipment. The vast majority of diesel vehicles in the Northwest are pickups. But more drivers are turning to diesel cars and SUVs, as they become cleaner and more fuel efficient.
Kevin Downing, from the Oregon Department of Environmental Quality, said it's a dramatic change from even just a few years ago.
"Compared to a pre-2010 vehicle, the emissions are reduced by somewhere around 90 percent," he said. "They're very low-emitting vehicles."
Some barriers to diesel ownership remain: Diesels typically cost more brand-new and the price per gallon usually exceeds gas. That's one reason why overall diesel ownership in the U.S. is a fraction of what it is in Europe. In some countries more than half the vehicles on the road are diesels.