Green Car Congress: German automotive companies launch “clean-diesel” marketing campaign in US A moderator on MyNissanLeaf posted the above. It's interesting that a diesel fanboy (who some have labeled as a troll for other reasons there) started a random "Yes "clean diesel" really is clean..." thread over about a week ago. Hmmm...
I wasn't able to find the thread on MyNissanLeaf about clean diesel, but are you implying that you don't think "clean diesel" is really "clean"?
In my opinion, you need to take all emissions into account, not just what comes out of the tailpipe, i.e., well-to-wheels comparisons.
Here is the emission comparison of a 33 MPG diesel and gasoline from EPA site. Jetta TDI - 308 g/mi tailpipe and 82 g/mi upstream. Focus SFE - 269 g/mi tailpipe and 66 g/mi upstream.
Here's a WTW emissions comparison of a PZEV gasoline version and a TDI version of the VW Passat... WTW GHG emissions - 351 (TDI); 416 (PZEV) Gas vs. Diesel Well-to-Wheels Emissions
Here is a comparison from EPA. 379 g/mi (TDI) and 443 g/mi (PZEV). EPA numbers include CO2 equivalent of the other gases. The difference is due to 34 MPG diesel vs. 25 MPG gas. 140hp 4 cylinders diesel vs. 170hp 5 cylinders gas.
Jetta/Hybrid/TDI comparison from EPA. Jetta (200hp Gas) - 410 g/mi Jetta (140hp TDI) - 379 g/mi Jetta (170hp Hybrid) - 246 g/mi
The problem with this concept is that diesel is $.90 a gallon more expensive than regular here. These car companies should look at that. I know I do and it totally turns me off of diesel.
I used the WTW GHG results of GREET1_2012 of the MT versions of each vehicle. Using the AT versions, GREET1_2012 gives 449 g/mi (PZEV) and 384 g/mi (TDI). Not sure what EPA is using, but the relative difference appears to be about the same.
