I have a friend with a Zr2 and he put 4" on it and is running 33x12.5r15s with 15x8 wheels. He said because the tires were so wide and wheels so narrow they actually measured 35" and I measured them and they were 34.5 (weared a bit). I was wondering if I did 31x10.5s on 15x7 wheels would I get the same effect? maybe not as drastic but a bit bigger???

 

Well, it all depends on the tire. Not all tires are made equal. Even though they say they are 31x10.50x15, they could be a bit taller or a bit shorter than that actual size.

This is interesting though, I need to measure mine tomorrow. I have 31x10.50x15s on 15x7 wheels. I'll let you know what mine measure within the next few days.

And are his 33s mud terrains? Super swampers? All terrains?

 

Yup, not all tires are created equal.

 

Ok thanks, his were BFG A/Ts

 

Sounds more like he's running them on too narrow of a rim and with too much air pressure if he has them balloned that far. You do get a small amount up and down depending on the brand but its never that much.

Bet his truck rides rough and doesn't get any traction aired up like that.

 

The thornbirds I had on my 96 were just as tall as the bfg at's on my friends s-10. I had mine on 15x8 and he had the stocker 15x7's. I had 29x10.50 and he had 31x10.50

 

I must not be measuring right.

It says my 31x10.50x15s are only 29.5 inches and these tires have only a couple hundred miles at most. Maybe 300 miles. This is crazy. If this is true, I might go with a 32 the next time around. This just doesn't add up though. Why would a 31 be 29.5 inches? I could understand if they were 30.5 or 31.5 or somewhere in between, but an inch and a half seems like a lot. Maybe I should check the air in my tires too lol.