Auto analyst throws cold water on U.S. dieselization

Diesel Fuel News, Feb 3, 2003 by Jack Peckham

Except for the biggest pickup trucks and sport-utility vehicles (SUVs) -- which already have loyal diesel buyers -- don't expect a big dieselization push in the U.S., according to 28-year veteran automotive analyst Phillip Gott, of Massachusetts-based Global Insight.

At Global Insight's Detroit-area conference last week, Gott cited the relatively low cost of U.S. fuel, extremely tough emissions challenges and lower-risk gasoline car strategies for automakers.

Despite recently-announced VW and Daimler plans to import some diesels to the U.S. in the near future, "the bottom line is that no-one has invested in [diesel vehicle] production capacity for the U.S. -- they're just taking a few of them from Europe," Gott told Diesel Fuel News in a post-conference interview.

Some of the current automaker talk about diesel might be nothing more than a public-relations ploy that "deflects attention from the gasoline future" and also might "minimize CAFE hikes and protect fleet composition," Gott said.

"One issue is that everyone's afraid of consumer reaction" to diesels, partly because of the poor-quality vehicles of the late 1970s, their "smoky/smelly" reputation and partly the relative lack of customer-friendly, clean diesel pumps at most "gas" stations in the U.S.

Another factor is the emergence of smaller, "crossover" gasoline SUVs that "appeal to many of the same buyers as full-size [SUVs] yet are smaller, lighter, inherently more energy efficient," he said.

Even if consumers balk at diesels due to perception issues, another major issue remains U.S. EPA and California Air Resources Board (CARB) "Tier-2" and "LEV-2" emissions regulations starting after 2004.

Partly because of the uncertainty over diesel catalyst development for nitrogen oxides (NOx) and particulate matter (PM), plus the inevitably higher costs for such catalysts, it's by no means certain that U.S. consumers will make a big move toward diesels, Gott said.

Recent automotive consulting studies show "diesel is not needed for CAFE [corporate average fuel economy]" legislation, as some other emerging technologies might provide "just enough" fuel economy boost to overcome declining U.S. fleetwide fuel-economy, at costs lower than dieselization.

One emerging fuel-savings technology deserving special attention is 42-volt electrical, which could enable a big reduction in parasitic power drain from belt-powered water pumps and power steering, he said. This technology is far less costly than changing over to diesel engines -- especially important since automakers want to minimize risk while maximizing return from their gasoline-based legacy "momentum."

As for diesel's fuel efficiency: neither the U.S. public, nor President Bush, nor Congress nor U.S. Department of Transportation seem to care much about it, he said.

Given that man-made [CO.sub.2] emissions are only about 3% of total [CO.sub.2], many question whether drastic CAFE adjustments can be justified economically, let alone dieselization.

While the 2003 VW Golf diesel produces half the [CO.sub.2] emissions of the same gasoline car, it produces four times more smog emissions, Gott said. Citing the controversial findings of Stanford University researcher Mark Jacobson, Gott points out that some diesels might cause worse global warming from. "black carbon" emissions than the [CO.sub.2] benefits from diesel's better fuel economy. (The "black carbon" claim however was later refuted by University of Minnesota diesel particle scientist David Kittelson, who cites the excellent carbon efficiency of diesel particulate filters).

What's more, even if diesels could hit EPA Tier 2 "bin 8" emissions limits by 2007, their maximum penetration could only reach 25% of the U.S. market, Gott shows. However, automakers instead are shooting for tougher "bin 5" limits in order to avoid the required offsetting sales of zero- or near-zero emissions "bin 1-2" cars, which net big losses on every unit sold.

* Post-Tier-2 Threat

What's worse, diesels eventually may have to achieve post-Tier-2 limits that could require unlimited catalyst performance/durability standards.

"Engines can easily get 200,000 miles now," well beyond the EPA-mandatory 120,000 miles mandate for "lifetime" light-duty vehicle catalyst performance, Gott said. "Vehicles will last well beyond these warranties, and we're convinced that the regulators will make [the catalysts] last forever."

That would be especially tough on diesels because of the likely need to clean-out ash accumulation from a diesel particulate filter (DPF), he said. The longer customers keep DPF-equipped vehicles, the more annoyed some might get over periodic DPF maintenance. The fear is that some of them will cut-off the DPF altogether, he said.

Given today's state-of-art knowledge of engine/exhaust aftertreatment technologies, diesels have only a 20% probability of "meeting the most stringent standards for PM and NOx" by 2010; a 40% chance by 2015 and a 60% chance by 2020, Goit predicts. By contrast, homogenous charge compression ignition (HCCI) would have an 85% chance of meeting such NOx/PM standards by 2010 (if anyone can ever figure out how to control an HCCI engine with today's pump fuels).