What's the sitting diameter of your 33's? My Procomp 305-65-17's are 31.75" at 40-psi and 17,000 miles. Anybody have or make a tire that nets out at 33...or just over?

 

285/75r16 Duratracs @ 33PSI. Measures exactly 32.25" tall.

My speedometer is dead on with my Procal with that measurement programed in too.

I hear Maxxis tires run close to advertised heights. I have no firsthand experience though.

 

Per the conversion, your tires come out to 32.6" tall. Add vehicle weight and you're pretty close. There are very few tires out there that run exactly as the advertised size. Some brands are notorious from running smaller than others. I'm not sure where Pro Comps stand, I've never run them.

 

My Cooper Discoverer STT in LT285/70R17 measure 33".

 

My 275/70/18 Duratracs measure out at 32.25" tall.

 

Goodyear MT/R 285/70R17 are 33"

You are right the numbers fluctuate with manufacturers, it irritates me as well.

 

Rim width also affects the height. Rule of thumb is take the stated or converted tire height than subtract an inch. Kind of like the Subway sandwich foot long not being a foot long.