CarSpecsHQ

265/30R20 vs 275/35R20

275/35R20 is outside the ±3% rule as a replacement for 265/30R20: the diameter differs by +5.02%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

20" rim
265/30R20 26.26" · 275/35R20 27.58" · drawn to scale

Side by side

265/30R20275/35R20Difference
Overall diameter26.26"27.58"+1.32" (+5.02%)
Section width265 mm275 mm+10 mm
Sidewall3.13"3.79"+0.66"
Rim20"20"same
Circumference82.5"86.6"+4.1"
Revs per mile768731-37
Ride height——+0.66"
Speedometer reads 60 mph60.063.0+3.0 mph

Speedometer and odometer

020406080100120 reads 60 · actual 63.0 mph

With 275/35R20 on a car calibrated for 265/30R20, the speedometer reads 57.1 mph when you're really doing 60, and the odometer under-counts by 5.0%.

Speedo showsActual speed
30 mph31.5 mph
45 mph47.3 mph
60 mph63.0 mph
70 mph73.5 mph
80 mph84.0 mph

Other sizes close to 265/30R20

Questions

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

275/35R20 is outside the ±3% rule as a replacement for 265/30R20: the diameter differs by +5.02%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

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

275/35R20 is 1.32" taller and 10 mm wider; the sidewall is +0.66". At an indicated 60 mph you'd actually be doing 63.0 mph.

Will 275/35R20 fit on 265/30R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.