Im not sure about mileage. But fewer cylinders means fewer parts to break. Fewer plugs to change.

My brother had a 99 ford v10. It couldnt even lay rubber. Well ok maybe an 8 ft patch but it was pretty pathetic. Towards the end he was getting 7mpg, city driving not towing. Was on his 3rd tc. And complained daily that it was gutless. He just traded it for a hemi. I remember the old 4x4 magazine tests of the v10. This is what they said. " It was a v10???"

The dodge v10 has more power but I cannot say its a good buy. Dont know about how the tranny likes it. IF you had the 6 speed with the dodge v10 I think you would be styling.

Now that 8.1 is another story Its got *****. Friend of mine has one. Very impressive. His curb weight is about 12k and he still motivates quickly.