CarSpecsHQ

245/30R20 vs 335/25R20

335/25R20 is outside the ±3% rule as a replacement for 245/30R20: the diameter differs by +3.13%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

20" rim
245/30R20 25.79" · 335/25R20 26.59" · drawn to scale

Side by side

245/30R20335/25R20Difference
Overall diameter25.79"26.59"+0.81" (+3.13%)
Section width245 mm335 mm+90 mm
Sidewall2.89"3.30"+0.40"
Rim20"20"same
Circumference81.0"83.5"+2.5"
Revs per mile782758-24
Ride height——+0.40"
Speedometer reads 60 mph60.061.9+1.9 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.9 mph

With 335/25R20 on a car calibrated for 245/30R20, the speedometer reads 58.2 mph when you're really doing 60, and the odometer under-counts by 3.1%.

Speedo showsActual speed
30 mph30.9 mph
45 mph46.4 mph
60 mph61.9 mph
70 mph72.2 mph
80 mph82.5 mph

Other sizes close to 245/30R20

Questions

Can I replace 245/30R20 with 335/25R20?

335/25R20 is outside the ±3% rule as a replacement for 245/30R20: the diameter differs by +3.13%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 245/30R20 and 335/25R20?

335/25R20 is 0.81" taller and 90 mm wider; the sidewall is +0.40". At an indicated 60 mph you'd actually be doing 61.9 mph.

Will 335/25R20 fit on 245/30R20 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.