My '94 came originally with 225/75-15 tires, I know that 31x10.5-15s where an option. Was there any difference in gearing between these two tire options or was just a different speedometer calibration? Thanks!

 

Yep, different axle gears:
- http://www.4crawler.com/4x4/4R_TechI...tml#DiffRatios

 

Unless the 31s were dealer installed...

 

Hmm, I guess I'll have to get under the truck and get dirty then. Thanks!

 

Or look at the place card in your door jamb.

http://www.4crawler.com/4x4/ToyVIN.shtml

 

I took a look at the place card. It reads G254 on the axle code. According to this site, that means 8" with 4.556 gears. It also shows that being the ratio for the 31" option tires. Now I'm even more confused...

 

Which means that whoever has put new tires on it over the years just put on OEM standard. They usually ask (because it is an option), or you have to request it.

 

So running 31x10.5s shouldn't be a problem? What about going to 32s or 33s, should I go to 4.88s for either of those sizes?

 

33's shouldn't be a problem. I would do it as need basis. 35's I would go 4.88's.

 

Alright, thanks man! Hopefully this winter I can sell my other truck (Ford Ranger) and get something going on the 4Runner (engine, lift, tires, etc.)...

 

the vin tag on the inside of the door jamb also states the stock tire size... mine said 225/75 r15 which is equals roughly 28" tires. so i have 4.30s

its to the right of the GAWR and has front tire size above the rear tire size, which are obviously the same lol.

 

Mine says 225/75-15 as well, but the axle code reads 4.56s...

 

From what I have seen, the door sticker almost always shows 225/75-15 even on trucks that came with the 31" tires.

 

Interesting. I wonder what that's all about...

 

well... sorry bout that lol... hella weird.

 

axle code isn't 100% either, the only way to truly tell is to jack a wheel up and spin it 720 degrees (open diff) and count the number of driveshaft revolutions

 

Before I buy tires I'll double check the axle ratios...