I believe Toyota will use their own diesel engine. They will offer a diesel soon, no doubt, as they do in the rest of the world. ULSD will not make it unaffordable, just look at Germany, where ULSD has been in use for several years. DIesels are encouraged in that country and are considered the "base" engine in some of their vehicles. Toyota uses their own inline 6 24 valve diesel and gasoline engine in their forklifts. It is around 4. 5 liter and is supposedly what they use in a medium truck in other parts of the world. Not turbocharged in the forklift, but a well built engine. Would be great in a pickup, but would not touch the preformance of the Cummins. I just wish the little ricers would offer a small truck (around the S-10 and Ranger size) with a diesel. Maybe after ULSD comes out here?