CarSpecsHQ

235/30R20 vs 335/25R20

335/25R20 is outside the ±3% rule as a replacement for 235/30R20: the diameter differs by +4.08%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

20" rim
235/30R20 25.55" · 335/25R20 26.59" · drawn to scale

Side by side

235/30R20335/25R20Difference
Overall diameter25.55"26.59"+1.04" (+4.08%)
Section width235 mm335 mm+100 mm
Sidewall2.78"3.30"+0.52"
Rim20"20"same
Circumference80.3"83.5"+3.3"
Revs per mile789758-31
Ride height——+0.52"
Speedometer reads 60 mph60.062.4+2.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.4 mph

With 335/25R20 on a car calibrated for 235/30R20, the speedometer reads 57.6 mph when you're really doing 60, and the odometer under-counts by 4.1%.

Speedo showsActual speed
30 mph31.2 mph
45 mph46.8 mph
60 mph62.4 mph
70 mph72.9 mph
80 mph83.3 mph

Other sizes close to 235/30R20

Questions

Can I replace 235/30R20 with 335/25R20?

335/25R20 is outside the ±3% rule as a replacement for 235/30R20: the diameter differs by +4.08%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 235/30R20 and 335/25R20?

335/25R20 is 1.04" taller and 100 mm wider; the sidewall is +0.52". At an indicated 60 mph you'd actually be doing 62.4 mph.

Will 335/25R20 fit on 235/30R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 335 mm tire and the fender clearance.