Guys deflated feeling...I'm running 315-70-17 MTZs at 31 or 32 psi, and they measure 33.75 diameter, what the f***. I paid for 35s !!!!

Ok, the Mickey Thompson booklet said they measure 34.6 but I'm still almost an inch off. The ride is good with the psi and gearing I'm using, but 35s should be 35s....

Measurements pls chaps.....315x70x17 MTZs.....

Edit, measurements on your rig, allowing for compression of tires from Jeep's weight. Cheers

 

When they say a tire is 35", it is measured off the vehicle. You do realize that when 4000 plus pounds is pushing down on somethin you will get a little bit of "squish".


edit: I just saw your edit about vehicle weight.

 

miata.net/garage/tirecalc.html

pretty good site for calculating how tall your tires actually are (without weight on them of course). also tells you by how much your speedo will be off by.

 

thanks, still wondering what other MTZ owners are getting Cheers

 

Id almost go so far to say thet no 35" tires measures out to a true 35" once mounted. This is not a new phenomena, and isn't likely to change. Maybe you should get 37s which would be closer to 35 when you add the vehicles weight.

 

My ProComps measured 34.7 when I went to reset to speedo.

 

I agree with you. 33.75 is less than I expected, wondering what other MTZ runners are getting ? Please include what PSI your running them at on replies, cheers

 

And then there is the talk of narrower rims giving an overall taller tire than wider rims. No clue how much height difference there might be between a 8 vs 10 vs 12 inch wide wheel on the same tire, but...

But yeah, I was surprised to find that my 295/75/16's, which Nitto lists at 33.27" tall measured out at 32" even.

 

Every inch less of wheel width will give you an additional .4" of tire height and conversely for every inch of additional wheel width you will lose .4" of tire height. Certainly that will vary from tire to tire but it's pretty close to accurate. It also gives you an idea when you see the tire manufacturers measure tire height and what wheel width was used as to where you will end up.

Then of course you have the squish factor of a half ton or more sitting on each individual tire.

 

Here's a site where you can put up to 4 tire sizes in at once.

h ttp://www.1010tires.com/tiresizecalculator.asp

By the way, most 35's measure less than 35", usually around 34.6; most 33's measure less than 33", usually around 32.8; etc. The actual height varies by mfr. Your 315/70/17 calculates out to be 34.36". The actual height will vary depending on the thickness of the lugs, manufacturing differences, width of wheels, etc.