General Motors Poised To Take On Abandoned Diesel Owners - But Hasn't That Ship Already Sailed?

I praise GM for this move. I'm enjoying a diesel SUV (3.0 L V6), and my calculations (via my fuel economy spreadsheet) tell me that in 20,000 miles of driving so far, I've saved between 34% to 40% in fuel cost per mile compared to a 2.0 liter gasoline engine in the same vehicle. Plus I have 0-60 mph times of 6.4 seconds available on tap, should I want it.

If GM has GENUINELY got their diesel emissions under control, then kudos to them! I wish the success.


*** PISS-OFF WARNING ***

While I recognized that the Volkswagen Audi Group (VAG) has been in the spotlight since September 2015 for their Dieselgate emissions cheating scandal, I also note that independent research has revealed that virtually ALL vehicles tested -- diesels, gasoline powered, and even some hybrids (!) -- regardless of brand, exceed (by far) the lab-legal emission levels when operating in the real world... and VW is NOT the worst emissions offender. Yet in the mind of Joe Average of America, VW and diesels specifically are the root of all emissions evils. I'm sure this post will inspire the ire of those readers who so dearly want to slam "dirty diesel" as being evil and worthy of banishment.

I'm with ya. While I truly enjoy my Passat TDI, I need to move back into a SUV/CUV for personal reasons. I bought a used Q5 to hold me over until the auto makers get their excrement in succession, and bring a decent hybrid/diesel to the SUV world. I know Audi has a TDI version of my Q5 (in fact you have one), and if I could have picked up a used one at a reasonable price that's what I would have bought. But now I can let the market settle down for a couple of years and see what comes. If the new Tiguan comes with a decent hybrid (the Jetta version was great) then VW will keep me. Otherwise this diesel Equinox may fill the bill. Since I haven't owned a GM since the early 80s, that may take some mental adjustment :)

The reason most diesels fared worse than tested is that the test has the cars driving under very unstressful situations (i.e.. engine warm, gentle acceleration, no hills etc), obviously real world driving differs from this. This is the same reason the EPA milage on most cars is very optimistic. VAG is the worst offender because they actively created software to detect when the vehicle was being tested and change the emission control parameters accordingly. What the others did is akin to studying for a test, what VW did is akin to cheating on the test.

Actually, your opening line is factually untrue. It's not JUST diesels that fare worse in the real world as compared to the in-lab-only tests. It's virtually ALL vehicles.

Secondly, these vehicles don't fare worse on the road than in the lab because "the test has the cars driving under very unstressful situations". It's because auto manufacturers design and tune their engines to pass the completely unrealistic in-lab-only test, so that's where they're shining stars. The in-lab tests, though reproducible, do not reflect real-world use in the least. That's a key point that's missed by many. If you have a reproducible crappy process (in-lab-only testing methodology), then whatever data you supply as the input (the vehicle being tested), you're sure to have reproducibly crappy data as the output (the vehicles alleged in-lab-only emission numbers).

Now that authorities have caught on to how useless these in-lab-only test are in reflecting the real-world, they're in the process of changing the testing methodology to use actual tailpipe emissions and actual fuel economy when the vehicle is on the road, under MUCH more actual-world conditions.

What I describe is very different than your dismissive and grossly inaccurate "explanation."


re "VAG is the worst offender because they actively created software to detect when the vehicle was being tested and change the emission control parameters accordingly."

Yes, this is exactly what Joe Average has been bamboozled into believing: VW is the baddest because they used a cheat device. Never mind all the other brands and models who have WORSE real-world emissions than VW's diesels, but didn't use a cheat device. In other words, their ignorance says "never mind real-world emissions, as long as you don't cheat on a meaningless in-lab-only test, you're good."

I believe that diesel could still be viable...just not ever again as a VW.