According to Mercedes-Benz, America’s dirty fuels, namely its high sulfur content in gasoline, is the main reason why we won’t be seeing a new generation of ‘lean-burn’ engine technology anytime soon.

Already on sale in Europe, these lean-burn engines run at a much leaner fuel-to-air ratio than conventional engines, improving fuel economy and emissions. Mercedes-Benz calls its lean-burn engines “Stratified” and says the technology can improve efficiency by as much as 10 percent. 

However, the technology requires gasoline with a sulfur content of less than 50 parts per million (ppm). The sulfur content of gasoline currently sold in the U.S. is around 95 ppm at the pump, while in Europe it is near zero. Interestingly, diesel fuel, which is much more regulated in this country than gasoline, has a sulfur content of just 15 ppm.

Thus, until fuel quality improves in this country, Mercedes-Benz won’t be able to introduce some of its more advanced engines.

This has already been seen with cars like the new 2012 Mercedes-Benz C-Class and upcoming SLK. Both 350 variants feature a new 3.5-liter V-6 engine, which in Europe is offered with direct injection and lean-burn capability. In the U.S. we only get the direct injection.

You can catch our first drive report on the 2012 Mercedes-Benz SLK350 by clicking here.

[Ward’s Auto]