Sorry, I missed this. Can you give me the size stamped in the sidewall? 24" tires on a truck can't be stock. Either that or you have a flat.

If they truly are 24", you don't need gears. You'd already be turning 2,400 rpm at 70. You'd be turning 2,550 rpm with 3.73s and 2,800 rpm with 4.10s.

 

they are 235/70r16s, but i measured them, from the center of the hub to the outside, and it was 12.2 inches. they may be under inflated

 

Based on revolution per mile data on tires in that range, they should be the equivalent of 28.1". Better inflate those puppies. It's better to make that measurement when they're been rolling for a while (hot). Here is a recap of your max speeds at max engine power (4,750 rpm), by the various ratios that have been thrown around. You don't have the power to reach the upper speeds because horsepower isn't enough to overcome wind and other variables to reach that rpm.

G/R 1st 2nd 3rd 4th rpm@70
3.55 39 72 112 160 2,076
3.73 37 68 106 152 2,181
4.10 34 62 97 139 2,397

I doubt you'd notice any loss in mileage in town, but on the highway, you could see some reduction. I don't think the loss at highway speeds with 4.10s would be more than a couple mpg. If you drive faster than that, the mileage penalty will be greater. If you tow and lock out of O/D, you rpm at 70 will be over 3,000 rpm with either ratio. Hope this helps.

 

yes it has, thank you for all the info.

 

what happens to gas milage and power if you put in smaller gears like...hmmm....say 2.83 or something like that..

 

well 1-your truck wouldnt have a lot of power starting out,2-more downshifting,3-probably be making the engine strain more to keep it going the same speed,4-a/c turning on would make it downshift probably from slowing down. only advantage would be if you did ALL highway driving you would see good mileage but the wind resistance at speed would play a bigger factor because it is more strain with those gears than a bigger gear. i had an 04 heritage(03 style) rec cab long bed and it had a 4.2L V6 with a 5 spd and 3.08 rear end. 0-60 was 9.58 seconds with a cold air intake and i had to downshift going up hills. but on highway i saw about 25-27 mpg with the intake

 

The 4.6 thrives on high revs and needs high revs, compared to a 5.4. The low end torque just isn't there in comparison.

 

I have a Edge Evo Tuner... With 35"x12.5" Tires... I can do 25-27MPG Driving on Long Drive....
City Driving or Hard Driving I do 16+

 

 

truth! I can't even average 16hwy with my 35s and edge. But I don't really care about gas per se, I use my truck for what it is.

 

Could be worse. Could be like Chevy and put a bow on it.