I have read quite a bit about the deisel jetta and real world test have it come out a little better then the hybrid prius. With the ULSD fuel and maybe some bio added it might be close to 90-95% clean.
"This is the single greatest achievement in clean fuel since lead was removed from gasoline a generation ago," says EPA Administrator Stephen Johnson. Starting Sunday, 80 percent of diesel fuel sold in the U.S. will be a cleaner, ultra low-sulfur emitting (ULSD) version that, while costing about 5 cents per gallon more, will dramatically reduce nasty particulate emissions. It's due to those biproducts -- and the tough emissions standards of California and the northeast states -- that diesel hasn't been as popular in the U.S. as it has in, say, Europe. Only 3.6 percent of cars in the U.S. are diesel-powered, while across the Atlantic, the number is almost 50 percent. The new fuel comes just in time for the delivery of Mercedes' diesel E320 sedan next week in 45 states; the company plans on releasing diesel cars that meet all states' standards by 2008. And Honda is preparing to enter the 50-state market in 2009, with its own innovative cleaner diesel engine (pictured), to be followed by Chrysler, GM, and VW and others.
Let the diesel invasion of the U.S. begin.
The cleaner (and quieter) 50-state-friendly engines, which will be offered in three of Mercedes Benz' sport-utility vehicles next year and in unnamed Honda models in 2009, boast improved combustion and better treatment of yucky and pesky nitrogen oxide emissions. While the Mercedes Bluetec engine will inject urea (yes, as in urine) to create the ammonia needed to scrub out nitrogen oxides, Honda's i-CTDi engine ingeniously creates ammonia on its own, by combining hydrogen with nitrogen inside a double-layer catalyst. That means not just cleaner emissions but potentially greater efficiency for the diesel engine -- which is already much more efficient (and, ahem, faster-accelerating) than a gasoline-powered one.
Honda has already made waves in the diesel tank earlier this year by patenting a treatment system that would use a plasma reactor -- a layer of gas -- to significantly reduce nitrogen oxides in its engine.
But such cleaning technologies can be energy-intensive, which is why the new low-sulfur fuel is so important: with less sulfur in the mix, emissions-control technologies can work more efficiently. Thus, cleaner-diesel engines become more enticing for automakers, who must comply with next year's strict new EPA rules for diesel engines.
Though diesel is expected to command up to a 12 percent market share by 2015, for now much of impact of the new regulations and technologies will likely be felt (or breathed) in the heavy-duty truck sector, where diesel is most commonly used.
And for the rest of us? While it's not as sexy as renewable energy, and is only part of an answer to our continuing energy challenge, the appeal of diesel -- with its higher torque, greater fuel economy, and lower carbon emissions than gasoline -- is rising.
The next natural step would be exploring how to make cleaner diesel hybrid engines. Add some biodiesel into the mix, and then you've got a really powerful vehicle for change.
