CarSpecsHQ

285/30R20 vs 265/35R20

265/35R20 is a safe swap for 285/30R20 by the usual ±3% rule: the diameter differs by +2.14%.

20" rim
285/30R20 26.73" · 265/35R20 27.30" · drawn to scale

Side by side

285/30R20265/35R20Difference
Overall diameter26.73"27.30"+0.57" (+2.14%)
Section width285 mm265 mm-20 mm
Sidewall3.37"3.65"+0.29"
Rim20"20"same
Circumference84.0"85.8"+1.8"
Revs per mile754739-16
Ride height——+0.29"
Speedometer reads 60 mph60.061.3+1.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.3 mph

With 265/35R20 on a car calibrated for 285/30R20, the speedometer reads 58.7 mph when you're really doing 60, and the odometer under-counts by 2.1%.

Speedo showsActual speed
30 mph30.6 mph
45 mph46.0 mph
60 mph61.3 mph
70 mph71.5 mph
80 mph81.7 mph

Other sizes close to 285/30R20

Questions

Can I replace 285/30R20 with 265/35R20?

265/35R20 is a safe swap for 285/30R20 by the usual ±3% rule: the diameter differs by +2.14%.

What's the difference between 285/30R20 and 265/35R20?

265/35R20 is 0.57" taller and 20 mm narrower; the sidewall is +0.29". At an indicated 60 mph you'd actually be doing 61.3 mph.

Will 265/35R20 fit on 285/30R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 265 mm tire and the fender clearance.