CarSpecsHQ

245/35R18 vs 265/35R18

265/35R18 is a safe swap for 245/35R18 by the usual ±3% rule: the diameter differs by +2.23%.

18" rim
245/35R18 24.75" · 265/35R18 25.30" · drawn to scale

Side by side

245/35R18265/35R18Difference
Overall diameter24.75"25.30"+0.55" (+2.23%)
Section width245 mm265 mm+20 mm
Sidewall3.38"3.65"+0.28"
Rim18"18"same
Circumference77.8"79.5"+1.7"
Revs per mile815797-18
Ride height——+0.28"
Speedometer reads 60 mph60.061.3+1.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.3 mph

With 265/35R18 on a car calibrated for 245/35R18, the speedometer reads 58.7 mph when you're really doing 60, and the odometer under-counts by 2.2%.

Speedo showsActual speed
30 mph30.7 mph
45 mph46.0 mph
60 mph61.3 mph
70 mph71.6 mph
80 mph81.8 mph

Other sizes close to 245/35R18

Questions

Can I replace 245/35R18 with 265/35R18?

265/35R18 is a safe swap for 245/35R18 by the usual ±3% rule: the diameter differs by +2.23%.

What's the difference between 245/35R18 and 265/35R18?

265/35R18 is 0.55" taller and 20 mm wider; the sidewall is +0.28". At an indicated 60 mph you'd actually be doing 61.3 mph.

Will 265/35R18 fit on 245/35R18 wheels?

Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 265 mm tire and the fender clearance.