Posted by Mark Williams | January 31, 2012

It seems like the timing is perfect. U.S. automakers are being pushed by state and federal regulations to increase their corporate average fuel economy (CAFE), and their marketing departments are falling all over themselves trying to prove their cars and trucks are saving the country from spending more on foreign oil, as both gas and diesel engine technologies seem to be advancing by leaps and bounds. 

So why don't we see more cars and trucks with new diesel engines or hear about them coming to market anytime soon? Sure, heavy-duty work trucks will continue to sell record numbers of bigger turbo-diesel engines, but nowhere else do we see that kind of interest. 

Lindsay Chappell of Automotive News even goes so far as to equate the diesel issue in this country to be a bit like soccer in his recent article. "Soccer is the most popular game in the world. But the prospect of Monday Night Football stepping aside for men in shorts is about as likely as U.S. auto companies ever replacing their gasoline engines with diesels," he wrote.

In his wonderfully laid-out article, Chappell is not optimistic about more diesels coming to the many U.S. vehicles. Among the most obvious issues regarding the complexity of the U.S. marketplace is the fact that in most places, diesel fuel costs more than gas, and in some cases it costs as much as 70 cents more per gallon compared with regular gas. When you look at the incredible efficiencies that powertrain engineers are getting out of current gas engines — through direct injection, turbocharging, air management, engine start/stop and advance intake and exhaust timing software — the gas-mileage benefits of a small turbo-diesel engine are not what they used to be. 

Companies like Honda, Toyota and Mazda, as well as all the premium German brands, have high-quality, small turbo-diesels that they sell in other markets but are skeptical about their ability to sell in large numbers in the U.S. 

"Their benefit is just not immediately obvious to U.S. consumers," says Dave Coleman, product development engineer at Mazda North American Operations in Irvine, Calif. "It requires some arithmetic and a calculator. The pump price of diesel is higher than gasolin, higher even than premium gas. And the diesel engine costs more to build, so it's more expensive to buy. So you have to calculate what your savings will be over years of driving."

Regardless, all the midsize and full-size pickup truck makers will have to seriously consider how they will achieve the mandated increases in fuel economy over the next several years. Companies like Ford seem to have a jump on the segment with the huge investment made in EcoBoost technology, but what will that mean to other companies? Chevy and GMC have small pickups coming to the U.S. market that will have to do a much better job than the current I-5 and V-8 options. It would be nice to have both turbocharged gas and diesel options in both the small and full-size half-ton segments, but we can only guess what that will do to base and premium packaging prices.