CarSpecsHQ

245/35R21 vs 265/35R21

265/35R21 is a safe swap for 245/35R21 by the usual ±3% rule: the diameter differs by +1.99%.

21" rim
245/35R21 27.75" · 265/35R21 28.30" · drawn to scale

Side by side

245/35R21265/35R21Difference
Overall diameter27.75"28.30"+0.55" (+1.99%)
Section width245 mm265 mm+20 mm
Sidewall3.38"3.65"+0.28"
Rim21"21"same
Circumference87.2"88.9"+1.7"
Revs per mile727713-14
Ride height——+0.28"
Speedometer reads 60 mph60.061.2+1.2 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.2 mph

With 265/35R21 on a car calibrated for 245/35R21, the speedometer reads 58.8 mph when you're really doing 60, and the odometer under-counts by 2.0%.

Speedo showsActual speed
30 mph30.6 mph
45 mph45.9 mph
60 mph61.2 mph
70 mph71.4 mph
80 mph81.6 mph

Other sizes close to 245/35R21

Questions

Can I replace 245/35R21 with 265/35R21?

265/35R21 is a safe swap for 245/35R21 by the usual ±3% rule: the diameter differs by +1.99%.

What's the difference between 245/35R21 and 265/35R21?

265/35R21 is 0.55" taller and 20 mm wider; the sidewall is +0.28". At an indicated 60 mph you'd actually be doing 61.2 mph.

Will 265/35R21 fit on 245/35R21 wheels?

Both use a 21" rim, so the wheel diameter matches; check the wheel's width range for a 265 mm tire and the fender clearance.