CarSpecsHQ

335/25R20 vs 285/35R20

285/35R20 is outside the ±3% rule as a replacement for 335/25R20: the diameter differs by +4.74%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

20" rim
335/25R20 26.59" · 285/35R20 27.85" · drawn to scale

Side by side

335/25R20285/35R20Difference
Overall diameter26.59"27.85"+1.26" (+4.74%)
Section width335 mm285 mm-50 mm
Sidewall3.30"3.93"+0.63"
Rim20"20"same
Circumference83.5"87.5"+4.0"
Revs per mile758724-34
Ride height——+0.63"
Speedometer reads 60 mph60.062.8+2.8 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.8 mph

With 285/35R20 on a car calibrated for 335/25R20, the speedometer reads 57.3 mph when you're really doing 60, and the odometer under-counts by 4.7%.

Speedo showsActual speed
30 mph31.4 mph
45 mph47.1 mph
60 mph62.8 mph
70 mph73.3 mph
80 mph83.8 mph

Other sizes close to 335/25R20

Questions

Can I replace 335/25R20 with 285/35R20?

285/35R20 is outside the ±3% rule as a replacement for 335/25R20: the diameter differs by +4.74%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 335/25R20 and 285/35R20?

285/35R20 is 1.26" taller and 50 mm narrower; the sidewall is +0.63". At an indicated 60 mph you'd actually be doing 62.8 mph.

Will 285/35R20 fit on 335/25R20 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.