Wow I must say that whole thing was quite the read, I think it may have answered my questions I've been having for a while now and if I understood everything correctly I've been going about better MPGs the wrong way however I am achieving one of my goals keeping it cool (temp wise)
To start I have an 05 Ram Quad Cab with the following:
G56 Transmission
3.73 rear axle
4" exhaust no cat just a Donaldson muffler
ATS manifold, k&n tube with AFE 7 layer filter
S&B intake elbow
EDGE juice with attitude
Cari lift (3" in front, and add a leaf in back)
35" toyo M/t's
My goal with this truck is to have something that is pretty to look at and get great(18+) gas mileage. So far its just easy on my eyes and not on the wallet. It would appear that my first mistake was putting the 35 M/T's, I knew the M/T's would hurt my MPG but going from my 305/55/20 (33.23) A/T tire to my 285/75/18 (35"x11.25) crushed my mpg's by about 5mpg. At first I thought it was due to the M/T tread but now it looks like it was me going to a 35" with my gearing ratio. Recently I was pulling a 26' horse trailer and my mpg was beyond horrible, under 12mpg. It was at this point I figured I needed to figure something out, my first thought was with a 34" highway tire now it looks like I might need to go smaller.So with the G56 and the 3.73 rear I should be looking more towards a 32"and under tire or because I have a G56 can I get away with a 34" highway tire and still get decent gas mileage. I know my mods to my truck may not let me get the 20+ mpg's but I would love to get as close to it as I can as I got 4 1600 mile trips in the next month 3 of which pulling a trailers.
Any advice you can give would be so greatly appreciated, and thanks for all the interesting posts from above.
ADDED: If I were to keep putting on 34/35" A/T and H/T tires what would be an optimal/cost efficient rear end a 4:10's?