Have you ever used a diesel from outside the US?
I've just received my new Citroen C5 - a good car with *wacky French* suspension design... I bought the 160bhp 2 liter diesel model and had to check twice when we got it home to be sure I didn't have the gasoline model. Very smooth, very refined and no indication (other than the filler cap) that the engine needs no spark plugs.
I get approx. 40mpg (US gal.) on mixed highway and suburban driving and am loving the 20,000 mile range between oil changes/services.
Take a look at diesels, you'll be surprised.