CarSpecsHQ

255/80R17 vs 285/75R17

285/75R17 is a safe swap for 255/80R17 by the usual ±3% rule: the diameter differs by +2.32%.

17" rim
255/80R17 33.06" · 285/75R17 33.83" · drawn to scale

Side by side

255/80R17285/75R17Difference
Overall diameter33.06"33.83"+0.77" (+2.32%)
Section width255 mm285 mm+30 mm
Sidewall8.03"8.42"+0.38"
Rim17"17"same
Circumference103.9"106.3"+2.4"
Revs per mile610596-14
Ride height——+0.38"
Speedometer reads 60 mph60.061.4+1.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.4 mph

With 285/75R17 on a car calibrated for 255/80R17, the speedometer reads 58.6 mph when you're really doing 60, and the odometer under-counts by 2.3%.

Speedo showsActual speed
30 mph30.7 mph
45 mph46.0 mph
60 mph61.4 mph
70 mph71.6 mph
80 mph81.9 mph

Other sizes close to 255/80R17

Questions

Can I replace 255/80R17 with 285/75R17?

285/75R17 is a safe swap for 255/80R17 by the usual ±3% rule: the diameter differs by +2.32%.

What's the difference between 255/80R17 and 285/75R17?

285/75R17 is 0.77" taller and 30 mm wider; the sidewall is +0.38". At an indicated 60 mph you'd actually be doing 61.4 mph.

Will 285/75R17 fit on 255/80R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 285 mm tire and the fender clearance.