New V-6 and V-8 Cummins engines are on the way. At the end of July, Cummins Inc. announced that it will "develop and manufacture a family of high-performance, light-duty diesel engines." This follows nine years of work with the Department of Energy, where the new V-6 and V-8 powerplants were tested in a Dodge Durango and a Ram 1500. So what happened?
Comparison of Phase 2 V-6 versus Phase 3 V-8
What happened was this: The new Cummins V-engines made great power, produced superior fuel mileage, were fairly quiet, and met the government's strict '07 emissions guidelines that require the exhaust to be cleaner than the air in Los Angeles. The results were so good that one phrase gets repeated over and over in DOE/Cummins documents: "There is a path to market for the light truck diesel." We think that's absolutely correct, and here's what we know about these engines that should be available by the '09 model year.
The Engines
The new Cummins diesels are a 4.2L (256ci) V-6 and a 5.6L (342ci) V-8, both using a 90-degree V-block design with aluminum heads and an iron block. They use single overhead camshafts, a new EGR system, a single turbo, common rail fueling with piezo injectors, and a diesel particulate filter. The V-6 weighs in at 663 pounds, and the V-8 tips the scales at 788 pounds, compared to the current 5.9L inline-six engines that weigh about 1,100 pounds.