[maxerickson]

Europe generally has more stringent regulation and worse pollution than the US. It's many more people in a smaller space.

Noise isn't a good predictor though, a muffler is a drain on efficiency.

[happyscrappy]

Actually the VWs that were emitting 40x pollution in the US were only 10x of the Euro regs.

[zardo]

Eu has stricter PM limits, the US has stricter NOx limits.

[happyscrappy]

http://www.hybridcars.com/will-america-avoid-europes-clean-d...