Vaguely unrelated, but petroleum politics, especially between the US And Europe are weird. I've got a diesel VW, I get roughly 40MPG, and my car has 3 catalyti

Vaguely unrelated, but petroleum politics, especially between the US And Europe are weird. I've got a diesel VW, I get roughly 40MPG, and my car has 3 catalytic converters in it. I live in California. Last year, my wife and I rented a diesel 7 series while in Europe (a minor upgrade to the car we had reserved). 70% of our driving was non-Autobahn, but still a lot in the 120kph range, with some traffic. 30% Autobahn, having fun. A larger car, a larger engine, comparable mix of driving to what I do at home, yet still roughly got 37MPH. Smaller diesel cars, we've started way north of what I get in my Jetta for even faster driving. Europe seems to have cleaner diesel (and air) yet fewer contraptions in their cars (compared to CA) and comparable or even larger cars there meet or exceed lesser cars here.