I still agree with the OP. Mileage is directly related to how hard you push an engine and the 1500 to 2500 fuel mileage comparison was still far from apples to apples. Did you notice the 1960lb curb weight difference? The 2500 sits taller and is less "flat" on the underside so it's cD is not the same as the 1500. Going down a level/flat road, the vast majority of fuel used is in overcoming wind resistance. Mechanical losses are actually pretty miniscule. That's way it takes 20 hp to go 60 mph in a sedan and over 600hp to go 200 mph.
Regardless, life, like engines, is a bunch of compromises. I'll take the big engine that returns 20 mpg and be just fine with it. If someone wants a 28 mpg truck, then they will need to accept the limitations that brings.
With that, I'm out of this one.
Adam
