So I did a flawless 360 mile highway trip yesterday in my truck. Held down 16mpg with no OD and the 36x12.5 TSL radials going 55. I think I passed the whole on-road section of the expedition vehicle test :D I'm pretty happy the ride was quite comfortable.

I just need to figure a way to get that MPG up a little bit more...

look in to an overdrive unit, i think it is gear vendors that has one

used nv4500 would help too

I think re-gearing will be more helpful towards increasing your mileage than an OD with 36" tires.

I figure for the little amount of time I spend on the highway its not worth the 4500 conversion. For the $3500 I could pay for alot of highway gas.