CarSpecsHQ

255/75R17 vs 33x12.50R17

33x12.50R17 is a safe swap for 255/75R17 by the usual ±3% rule: the diameter differs by +2.94%.

17" rim
255/75R17 32.06" · 33x12.50R17 33.00" · drawn to scale

Side by side

255/75R1733x12.50R17Difference
Overall diameter32.06"33.00"+0.94" (+2.94%)
Section width255 mm318 mm+63 mm
Sidewall7.53"8.00"+0.47"
Rim17"17"same
Circumference100.7"103.7"+3.0"
Revs per mile629611-18
Ride height——+0.47"
Speedometer reads 60 mph60.061.8+1.8 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.8 mph

With 33x12.50R17 on a car calibrated for 255/75R17, the speedometer reads 58.3 mph when you're really doing 60, and the odometer under-counts by 2.9%.

Speedo showsActual speed
30 mph30.9 mph
45 mph46.3 mph
60 mph61.8 mph
70 mph72.1 mph
80 mph82.3 mph

Other sizes close to 255/75R17

Questions

Can I replace 255/75R17 with 33x12.50R17?

33x12.50R17 is a safe swap for 255/75R17 by the usual ±3% rule: the diameter differs by +2.94%.

What's the difference between 255/75R17 and 33x12.50R17?

33x12.50R17 is 0.94" taller and 63 mm wider; the sidewall is +0.47". At an indicated 60 mph you'd actually be doing 61.8 mph.

Will 33x12.50R17 fit on 255/75R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 318 mm tire and the fender clearance.