We are talking about highly efficient engines which have 25%+ more power than the same model of car sold in the US - Due to the lack of proper laws the European models with all their efficiency can't be sold in the US "as is" and have to be detuned for the US market.

Genixia mentioned this as well:

Europe has had clean diesel laws in effect for a few years now, and this in turn has led to clean and powerful diesel engines for cars. (eg VW's 1.9TDi, 130BHP & 50mpg) In the meanwhile, US is lagging (again), so the US equivalent of that same engine only outputs 90BHP

How come a lack of laws in the US, as compared to Europe, means the 130BHP version can't be sold there? Surely "Dude, I just got 40 more horsepower" is about as American a car-buying sentiment as one could wish for? Is the grade of diesel different or something?

Peter