5.7 hemi is rated as high as 20 mpg. My dad averages 20 mpg with his 2012 hemi, but spend 30 seconds in the passing lane, or tow a trailer and that number will change quickly.
V6 gas truck is rated at 25.
I would think that the diesel v6 would outperform the gas v6 under any kind of load and maintain high mpg while the gas engine's mpg would suffer under load.
I think diesel 1/2 ton trucks will sell like hotcakes.
