In January 2010, the DOE provided Cummins with $15 million to help fund development of an efficient diesel for light-truck use. Cummins began work last September with a goal to produce a diesel engine that would nearly double the efficiency of a Nissan Titan equipped with the current gasoline 5.6L V8 engine while not exceeding strict Tier 2 Bin 2 emissions standards. According toPickupTrucks.com,Cummins hopes to achieve 28 mpg combined with the new engine. A two-wheel drive Titan is currently rated at 15 mpg combined city and highway.

According to a DOE report, Cummins has focused on various areas to achieve its fuel and emissions goals. One priority is the expansion of low-temperature combustion (LTC) which should result in very low emissions. For added durability, the prototype engine contains high-strength steel pistons, which are stronger than aluminum pistons commonly found in most gas or diesel engines. Nitrogen oxide emissions will be kept at bay by the use of exhaust fluid already used in current heavy-duty diesel trucks.

PickupTrucks.comreports that the prototype engine--likely based on the European market Cummins ISF2.8--produced 350 lb-feet of torque during a recent dyno test. Cummins has set the final target output at 220 hp and 380 lb-ft of torque. The Titan's V8 puts out a bit more (317 hp and 385 lb-ft of torque), but with the current cost of gasoline, and the significantly better projected fuel economy, we're willing to bet consumers would be willing to go with the diesel engine.

While most truck makers as of late have been tweaking their gas engines with direct injection (and turbos in the case of the Ecoboost V6 found in the Ford F-150) to meet upcoming fuel economy standards, Cummins is proving that high-efficiency diesels could be a tough competitor and are even more efficient than gasoline-powered counterparts. According to a DOE report, 119 million barrel of oil per year could be saved if just 30 percent of light trucks in the United States switched to Cummins' prototype engine (assuming it meets the proposed targets).

Thanks to Mike Levine at PickupTrucks.com for use of the photos!