Gm 6.0 litre v v t v8 tow vehicle engine

[james schaechter]

I love my duramax I irdered it new in2002 6 speed stick 4 x 4. It was 35k out the door and has 347,000 on it. I avg 20 mpg in the Chicago suburbs. Problem for me is that a comparable replacement is 65k or more.
I have been looking into. 2500hd gasser but the talk about 6.0 liters is discouraging. All of the diesels suffer on mpg with the emissions so it is really hard to justify.
My brother has a suburban 1500 with a 5.3 and I towed straight through from belle rise to Illinois once with no issues getting 10 mpg. I guess I assumed , more cubes and an Allison six speed would be hard to beat. I only have a 24 ft trailer , but I guess I need to do more research.