
Originally Posted by
ATLGt
Sulfur wasn't the fault of the diesel cars, it was the fault of our (U.S.) old fuel standard on diesel fuels. Now with low sulfur fuels, you can run cats like most of the cars over in EU and pass EPA emissions. The problem is is that NOx regulations in Cali are very high, so most have to inject more fuel on the exhaust stroke to burn off the extra O2 left. This is why we will never see the same numbers as EU diesels. I would not be surprised if this does get released here, it will have lower actual MPG rating (I say actual because EPA has changed their rating style which is why VW had an independent lab redo their mpg rating on their new diesels). They do have NOx regulations in EU, but they are mostly on larger vehicles and most of those get rid of the NOx by injecting ammonia in the down pipe.