New GM diesel to get almost 30 mpg in full size trucks

Even though the Senate has now passed a new energy bill that includes requirements for fleet fuel economy average of 35mpg by 2020 we still have a ways to go before the House passes it, the bill gets reconciled and ultimately signed into law. Nonetheless, the car makers have to get down to work and start cranking up the fuel economy of their vehicles, especially the larger trucks. All three of the domestic automakers have announced plans to add new diesel engines for their light duty trucks by the end of the decade with GM announcing a 4.5L V-8 and Chrysler last week mentioning plans to add a new smaller Cummins diesel to their Ram 1500 models.

The problem with the diesels, especially the newer clean diesels, is that they are more expensive to produce than gas engines. During our recent dinner with Gary Smyth of GM he indicated that the total coast of a clean diesel powertrain is about twice that of gas. The diesel engines do work though with the new GM diesel estimated to get close to 30mpg on the highway when mated to a conventional six speed automatic. If the new engine were to be matched up to the Two-Mode hybrid system, mileage in the mid-thirties would not be out of the question for the big trucks but at an added cost of several thousand dollars.

[Source: Automotive News - Sub. req'd, thanks to Mike for the tip]