Yup, what Drew said... you have to factor in all of the added weight in the truck, front & back & trailer...

 

I had an 04 ram with the 4.7 and 20" wheels 3.92 gears, I've towed upwards of 8,000 with it and got 11mpg w/o over drive (this was back in Oklahoma and Texas "flat lands"). Never had much trouble getting it rollin or stopping in the "flat lands" but if you have alot of hills think it over. I put in 4.56 gears and that really made a difference takin off though, I didn't like the idea of towing that kinda weight with a 4.7 gasser though so I bought my CTD... today [sm=goodidea.gif].