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33x12.50R20 vs 285/60R20

285/60R20 is a safe swap for 33x12.50R20 by the usual ±3% rule: the diameter differs by +1.41%.

20" rim
33x12.50R20 33.00" · 285/60R20 33.46" · drawn to scale

Side by side

33x12.50R20285/60R20Difference
Overall diameter33.00"33.46"+0.46" (+1.41%)
Section width318 mm285 mm-33 mm
Sidewall6.50"6.73"+0.23"
Rim20"20"same
Circumference103.7"105.1"+1.5"
Revs per mile611603-8
Ride height——+0.23"
Speedometer reads 60 mph60.060.8+0.8 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.8 mph

With 285/60R20 on a car calibrated for 33x12.50R20, the speedometer reads 59.2 mph when you're really doing 60, and the odometer under-counts by 1.4%.

Speedo showsActual speed
30 mph30.4 mph
45 mph45.6 mph
60 mph60.8 mph
70 mph71.0 mph
80 mph81.1 mph

Other sizes close to 33x12.50R20

Questions

Can I replace 33x12.50R20 with 285/60R20?

285/60R20 is a safe swap for 33x12.50R20 by the usual ±3% rule: the diameter differs by +1.41%.

What's the difference between 33x12.50R20 and 285/60R20?

285/60R20 is 0.46" taller and 33 mm narrower; the sidewall is +0.23". At an indicated 60 mph you'd actually be doing 60.8 mph.

Will 285/60R20 fit on 33x12.50R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 285 mm tire and the fender clearance.