I have come across killer deals for 37 in tires I can get them anywhere from 30-80 each they are bfg bajas and other mud terrains my question is this. I have a 1986 4runner with the 22re with stock gearing im running 33x12.5x15 atm and average 18mpg but this weekend im replacing injectors, headgasket, water pumo etc etc if I do the 37x12.5 tires with 5.38 gears will this keep my gas mileage around 18mpg? Was gunna stick with 33s but thats a good deal on nearly new 37s please help me out I dont wanna sink the money into the truck just to be disappointed anyone have any input?

Thanks in advance

 

If you're talking about the military surplus tires they are 16.5's and you also need rims.

5.29's is the gears you will NEED to turn those heavy suckers, especially with a 22RE.

 

I had 37" all terrains with 4.88s on my 84. It did fine but now has heavy and wide 35x15.5 tsls. It tops out at 70-75 an holds 5th fine. I feel the width is more of a factor than the height when highway speeds are involved. My 2 cents. My 88 3.0 has 5.71s with 38.5" tsls and its too much in my opinion. 5.29s would have been ideal for it