VW diesels are some of the dirtiest engines on the road. I'm not defending gas, but your VW at 45 mpg produces far more pollution than any 40 (or even 25) mpg gas powered vehicle.oilerlord said:DucRider said:If all you are looking at is CO2 vs a gas ICE, that is true. Your VW TDI in "cheat mode" is actually much better than that: ~110 g/km or 177 g/mile at the tailpipe
Real world testing CO2 levels on TDI's puts CO2 @~250 to 400 g/m. Add in upstream GHG of 58 g/m (CO2 of US diesel for a 40 mpg vehicle) and that puts you at 300+ g/mile
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The biggest issue with diesels is NOx
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Your VW (with the lean NOx trap) dynos @ .022 g/km or well within the EPA .043 g/km limit.
Real world measurements are a different story - up to 70 times the legal limit has been observed, and 2012 vintage TDI's test at levels that vary between .62 and 1.5 g/km depending on driving conditions.
Google NOx effects and you'll find links as to how nasty it is.
Gary, you're splitting hairs. My VW generally returns about 45mpg on the freeways of the Phoenix valley. There are a lot of old smoking V-8 clunkers, and monster trucks in the valley that are doing a lot more damage to the environment that my car is, so I'm comfortable with the choice I made going with a very fuel efficient car. While I don't disagree that diesel is bad - gasoline isn't necessarily "clean" either, so please don't defend it.
Much of what you like about the car (efficiency and torque/power) is a direct result of VW making a conscious decision to exceed allowed emissions by many magnitudes. I know (from previous discussions) that you're entirely comfortable with the amount of pollution it produces. I just wanted to make it clear that it is not in any way as "clean" as a 40 mpg gas car as you claimed earlier. The mpg equivalency produced by the calculators have an inherent assumption that the ICE vehicle meets emission standards.
You are certainly free to rationalize driving your "fuel efficient" VW. Just don't confuse fuel efficient with clean.