Lutz: GM Will Have Tier 2 Bin 5 Diesel Passenger Cars in North America, But Diesel is Not a “Panacea”
In a recent video post on GM’s Fast Lane blog, GM Vice Chairman Bob Lutz confirmed that the automaker would be introducing V-6 and all-aluminum V-8 diesel engines in light-duty diesel passenger vehicles into the North American market soon.
He noted that the Tier 2 Bin 5 emissions standards can “only be met through the use of urea“—i.e., with the use of a urea Selective Catalytic Reduction system for NOx control—and that broadly, GM light-duty diesels will likely not be a fifty-state solution for the US.
The good news is the standard [Tier 2 Bin 5] can be met. The bad news is that meeting these standards is about another $2,000 to $2,800 of emissions hardware and control systems on top of the already existing premium of a diesel engine over a gasoline engine which is anywhere between $1,000 and $2,000.
Making vehicles Bin 5 Tier 2 compliant is not the answer to a low-cost CAFE solution...I’m just cautioning you, do not assume that the diesel engine is the panacea and it’s going to get everybody to a fleet of 36 mpg.
In fact, even with Euro 5 [a more lenient standard than Tier 2 Bin 5], many European producers, including ourselves, are starting to ask ourselves, “Are the buyers of smaller cars actually going to pay a $4,000 - $4,500 premium to get a diesel engine which...the tougher the emissions you meet with diesels, the more the fuel economy advantage of diesels versus the modern gasoline engine shrinks?”—Bob Lutz
Although diesel starts out with a significant advantage in lower fuel consumption over conventional gasoline engines, that advantages is being whittled away by increasing emissions requirements on the diesel, and increasing efficiency in gasoline engines, Lutz said.
With the modern Tier 2 Bin 5 engine, Lutz said, the diesel fuel economy advantage will be sharply reduced to around 15% improvement or maybe even only 12%.
Lutz pointed the use of gasoline direct injection as one of the enablers for increasing gasoline engine efficiency in the short term. In the medium-term, the advent of the homogeneous stratified charge gasoline engine will basically eliminate the differences between gasoline and diesel, Lutz said.
GM is about half-way through a three-year project working with supplier Robert Bosch and Stanford University to accelerate development of HCCI (homogeneous charge compression ignition) engines. (Earlier post.)
At best, the diesel engine in the future is going to be tremendously expensive, it’s going to have a sharply reduced fuel economy advantage over gasoline engines, and it’s not going to be a fifty state solution. It’s going to be minus California and minus whatever states adopt California standards.—Bob Lutz