CarSpecsHQ

275/30R20 vs 265/35R20

265/35R20 is outside the ±3% rule as a replacement for 275/30R20: the diameter differs by +3.05%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

20" rim
275/30R20 26.50" · 265/35R20 27.30" · drawn to scale

Side by side

275/30R20265/35R20Difference
Overall diameter26.50"27.30"+0.81" (+3.05%)
Section width275 mm265 mm-10 mm
Sidewall3.25"3.65"+0.40"
Rim20"20"same
Circumference83.2"85.8"+2.5"
Revs per mile761739-23
Ride height——+0.40"
Speedometer reads 60 mph60.061.8+1.8 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.8 mph

With 265/35R20 on a car calibrated for 275/30R20, the speedometer reads 58.2 mph when you're really doing 60, and the odometer under-counts by 3.0%.

Speedo showsActual speed
30 mph30.9 mph
45 mph46.4 mph
60 mph61.8 mph
70 mph72.1 mph
80 mph82.4 mph

Other sizes close to 275/30R20

Questions

Can I replace 275/30R20 with 265/35R20?

265/35R20 is outside the ±3% rule as a replacement for 275/30R20: the diameter differs by +3.05%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 275/30R20 and 265/35R20?

265/35R20 is 0.81" taller and 10 mm narrower; the sidewall is +0.40". At an indicated 60 mph you'd actually be doing 61.8 mph.

Will 265/35R20 fit on 275/30R20 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.