CarSpecsHQ

235/50R20 vs 245/50R20

245/50R20 is a safe swap for 235/50R20 by the usual ±3% rule: the diameter differs by +1.35%.

20" rim
235/50R20 29.25" · 245/50R20 29.65" · drawn to scale

Side by side

235/50R20245/50R20Difference
Overall diameter29.25"29.65"+0.39" (+1.35%)
Section width235 mm245 mm+10 mm
Sidewall4.63"4.82"+0.20"
Rim20"20"same
Circumference91.9"93.1"+1.2"
Revs per mile689680-9
Ride height——+0.20"
Speedometer reads 60 mph60.060.8+0.8 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.8 mph

With 245/50R20 on a car calibrated for 235/50R20, the speedometer reads 59.2 mph when you're really doing 60, and the odometer under-counts by 1.3%.

Speedo showsActual speed
30 mph30.4 mph
45 mph45.6 mph
60 mph60.8 mph
70 mph70.9 mph
80 mph81.1 mph

Other sizes close to 235/50R20

Questions

Can I replace 235/50R20 with 245/50R20?

245/50R20 is a safe swap for 235/50R20 by the usual ±3% rule: the diameter differs by +1.35%.

What's the difference between 235/50R20 and 245/50R20?

245/50R20 is 0.39" taller and 10 mm wider; the sidewall is +0.20". At an indicated 60 mph you'd actually be doing 60.8 mph.

Will 245/50R20 fit on 235/50R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 245 mm tire and the fender clearance.