I currently have 305/60 18 tires which are supposed to be a 33x12.50 but only measure out to barely 32 inches. I want to upgrade to 325/60 18 but I want to be sure these tires will be a true 33" tire. Can someone who has these please go out and measure the actual diameter of them? Also include what kind of tires they are. Thanks!

 

Uh.


The actual size will vary based on manufacturer and the rim width they're mounted on. 325/60R18 spec at 33.5 inches, so I imagine they're in the ball park of 33" no matter where they come from. 305/60R18s spec at 32.5, so I don't know why you thought they would exceed the spec to be 33s?

Easy solution... add 60% of 2cm to overall height, and there's the difference. So basically they're 1.2" taller, so they should be a 33" tire.


My 295/70/18s measure out to a real 34" tall, and spec at 34.3".

 

That's why I said to include what kind of tires they are, and rim width doesn't affect height

 

Rim width affects setion width. If the tire has three sides of unalterable physical length, and the section width changes, then VIOLA something has to give. Stretch a pair of 235/75/16s over a 10" rim and tell me what happens, other than some seriously messed up tread wear.

Metric conversions are screwed up, buy Super Swampers if you care about Imperial measurements.

 

rim with does affect height a too narrow wheel wheel make the tire taller at the center and wear on the center tread first. A too wide wheel will make it wear on the outside edges first. So proper sized wheels will make it wear evenly across. If you have stock wheels they are probably 8 ins in width which will work for a 12.5in tire but you will wear the center down faster than the rest of the tire.

 

I have 12" wide wheels and these tires are worn very evenly. I also know someone with the same size tire on a 10" wide rim and they still measure 32". I really don't think rim width affects tire height.

 

Instead of running a metric sized tire. Why not buy a 33/12.50/18 or something of that nature. I know they are to find because i have 18s on my truck but i think Nitto makes the size you are looking for. and i know BF goodrich does because that is what i have on mine. But mine are on a stock wheel. Also 4wheelparts.com has a tire calculator on their site.