DETROIT -- Steve Kiefer, General Motors' vice president of global powertrain, said he is considering a diesel engine for the light-duty Chevrolet Silverado and GMC Sierra to counter fuel economy improvements due on the Ford F-150 and Ram pickups.
He also said GM engineers are working to improve the cylinder cutoff system already on the trucks. The system turns off half an engine's cylinders when the vehicle is cruising.
The 4.3-liter, V-6-powered Silverado and Sierra are EPA rated at 24 mpg on the highway. That is better than the 23 mpg of the most fuel-efficient 2014 F-150 but is 2 mpg behind the V-6 powered Ram 1500.
GM's full-sized pickups, however, soon will be chasing the competition. A Ram powered by an available 3.0-liter diesel V-6 goes on sale next month with a highway EPA rating expected to be around 28 mpg.
Ford officials are shooting for the same or better when the redesigned F-150 arrives this fall. The aluminum-intensive pickup shaves between 550 and 700 pounds of weight and will be available with a new compact 2.7-liter turbocharged V-6.
The good news for GM is that it has a diesel for its pickups ready to go. GM engineers designed a 4.5-liter diesel V-8, but the project was put on ice when the company spiraled into bankruptcy in 2009.
"We are looking closely at diesel entrees in that segment," Kiefer said. "In fact, I heard the term 'dust off' that 41/2-liter at one point. That is certainly one of the options. Clearly, we have a portfolio of diesel engines."
The 4.5-liter V-8 was to be built in GM's Tonawanda, N.Y., engine plant. GM had gone as far as clearing factory floor space and installing the transfer lines in 2008.
Though the engine was advanced for its time, with a single turbocharger mounted between the cylinder heads and other innovations, GM would likely redesign the engine -- possibly reducing displacement -- and adopting the latest friction reduction technologies.