CarSpecsHQ

245/30R20 vs 265/30R20

265/30R20 is a safe swap for 245/30R20 by the usual ±3% rule: the diameter differs by +1.83%.

20" rim
245/30R20 25.79" · 265/30R20 26.26" · drawn to scale

Side by side

245/30R20265/30R20Difference
Overall diameter25.79"26.26"+0.47" (+1.83%)
Section width245 mm265 mm+20 mm
Sidewall2.89"3.13"+0.24"
Rim20"20"same
Circumference81.0"82.5"+1.5"
Revs per mile782768-14
Ride height——+0.24"
Speedometer reads 60 mph60.061.1+1.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.1 mph

With 265/30R20 on a car calibrated for 245/30R20, the speedometer reads 58.9 mph when you're really doing 60, and the odometer under-counts by 1.8%.

Speedo showsActual speed
30 mph30.5 mph
45 mph45.8 mph
60 mph61.1 mph
70 mph71.3 mph
80 mph81.5 mph

Other sizes close to 245/30R20

Questions

Can I replace 245/30R20 with 265/30R20?

265/30R20 is a safe swap for 245/30R20 by the usual ±3% rule: the diameter differs by +1.83%.

What's the difference between 245/30R20 and 265/30R20?

265/30R20 is 0.47" taller and 20 mm wider; the sidewall is +0.24". At an indicated 60 mph you'd actually be doing 61.1 mph.

Will 265/30R20 fit on 245/30R20 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.