Europeans have I fuel costs because of high taxes. Also, their cars have to be smaller because they live in tight-knit metro areas and not the sprawling suburban areas that we in the U.S. do. That means tighter turns and narrower/smaller roads. This is also why their cars are tuned to handle better. They also have less emissions and safety restrictions than the U.S. does, which allows for lighter cars and more efficient engines b/c of a lack of power sapping and weighty emissions equipment. This then allows them to use highly efficient diesel engines.
With all of the regulations, and they grow every year, manufacturers have a much harder time meeting these regulations. Saftey systems and structures = more weight, which leads to the need for a more powerful engine..and so on.
