its a v8 diesel. RAM considered the cummins 8 for the 1500 based on their HD relationship with cummins, but in the end its still a V8. Diesel or not a V6 is always more fuel efficient.
equal displacement 8 vs 6 the 6 is more efficient, I said what I meant.Not sure I agree with the generalized statement that "a V6 is always more fuel efficient".
I agree in this case, the V6 will be more efficient than the V8. But it has to do with displacement, not the number of cylinders. Perhaps you meant to say "The 3.0 is always more fuel efficient than the 5.0"
Fewer cylinders usually means smaller displacement, but not always. The Cummins diesel in the Ram HD has only 6 cylinders and is less efficient than the Cummins V8.