CarSpecsHQ

285/30R20 vs 295/35R20

295/35R20 is outside the ±3% rule as a replacement for 285/30R20: the diameter differs by +5.23%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

20" rim
285/30R20 26.73" · 295/35R20 28.13" · drawn to scale

Side by side

285/30R20295/35R20Difference
Overall diameter26.73"28.13"+1.40" (+5.23%)
Section width285 mm295 mm+10 mm
Sidewall3.37"4.06"+0.70"
Rim20"20"same
Circumference84.0"88.4"+4.4"
Revs per mile754717-37
Ride height——+0.70"
Speedometer reads 60 mph60.063.1+3.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 63.1 mph

With 295/35R20 on a car calibrated for 285/30R20, the speedometer reads 57.0 mph when you're really doing 60, and the odometer under-counts by 5.2%.

Speedo showsActual speed
30 mph31.6 mph
45 mph47.4 mph
60 mph63.1 mph
70 mph73.7 mph
80 mph84.2 mph

Other sizes close to 285/30R20

Questions

Can I replace 285/30R20 with 295/35R20?

295/35R20 is outside the ±3% rule as a replacement for 285/30R20: the diameter differs by +5.23%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 285/30R20 and 295/35R20?

295/35R20 is 1.40" taller and 10 mm wider; the sidewall is +0.70". At an indicated 60 mph you'd actually be doing 63.1 mph.

Will 295/35R20 fit on 285/30R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 295 mm tire and the fender clearance.