CarSpecsHQ

235/85R16 vs 285/75R16

285/75R16 is outside the ±3% rule as a replacement for 235/85R16: the diameter differs by +3.47%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

16" rim
235/85R16 31.73" · 285/75R16 32.83" · drawn to scale

Side by side

235/85R16285/75R16Difference
Overall diameter31.73"32.83"+1.10" (+3.47%)
Section width235 mm285 mm+50 mm
Sidewall7.86"8.42"+0.55"
Rim16"16"same
Circumference99.7"103.1"+3.5"
Revs per mile636614-21
Ride height——+0.55"
Speedometer reads 60 mph60.062.1+2.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.1 mph

With 285/75R16 on a car calibrated for 235/85R16, the speedometer reads 58.0 mph when you're really doing 60, and the odometer under-counts by 3.5%.

Speedo showsActual speed
30 mph31.0 mph
45 mph46.6 mph
60 mph62.1 mph
70 mph72.4 mph
80 mph82.8 mph

Other sizes close to 235/85R16

Questions

Can I replace 235/85R16 with 285/75R16?

285/75R16 is outside the ±3% rule as a replacement for 235/85R16: the diameter differs by +3.47%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 235/85R16 and 285/75R16?

285/75R16 is 1.10" taller and 50 mm wider; the sidewall is +0.55". At an indicated 60 mph you'd actually be doing 62.1 mph.

Will 285/75R16 fit on 235/85R16 wheels?

Both use a 16" rim, so the wheel diameter matches; check the wheel's width range for a 285 mm tire and the fender clearance.