Was looking at both the 1500 series Chevy and the Tundra's. Liked the fact the Chevy 5.3L had the cylinder deactivation system, but when I read about some problems in the past with it I didn't want to be a ginny-pig. Looked at double cabs in both. The Tundra double cab was much larger in back by maybe 4 or 5" of leg room. Ended up ordering a 5.7L Tundra.
Yes, the E85 will reduce MPG by 20% to 30%. The problem is that there is so much corn being produced to make E85 they are up against what is called the "blend wall"
The corn lobby is pushing to stretch / raise the wall to force you and me to buy more E85 and lower our MPG's. I tried to order a Tundra with out the E85 engine, but they said you have to take the E85 / Flex Fuel engine in Ohio. Even thou there is an option for the non-E85 5.7L.