CarSpecsHQ

285/70R17 vs 33x12.50R17

33x12.50R17 is a safe swap for 285/70R17 by the usual ±3% rule: the diameter differs by +0.89%.

17" rim
285/70R17 32.71" · 33x12.50R17 33.00" · drawn to scale

Side by side

285/70R1733x12.50R17Difference
Overall diameter32.71"33.00"+0.29" (+0.89%)
Section width285 mm318 mm+33 mm
Sidewall7.85"8.00"+0.15"
Rim17"17"same
Circumference102.8"103.7"+0.9"
Revs per mile617611-5
Ride height——+0.15"
Speedometer reads 60 mph60.060.5+0.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.5 mph

With 33x12.50R17 on a car calibrated for 285/70R17, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.9%.

Speedo showsActual speed
30 mph30.3 mph
45 mph45.4 mph
60 mph60.5 mph
70 mph70.6 mph
80 mph80.7 mph

Other sizes close to 285/70R17

Questions

Can I replace 285/70R17 with 33x12.50R17?

33x12.50R17 is a safe swap for 285/70R17 by the usual ±3% rule: the diameter differs by +0.89%.

What's the difference between 285/70R17 and 33x12.50R17?

33x12.50R17 is 0.29" taller and 33 mm wider; the sidewall is +0.15". At an indicated 60 mph you'd actually be doing 60.5 mph.

Will 33x12.50R17 fit on 285/70R17 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.