CarSpecsHQ

295/40R20 vs 245/50R20

245/50R20 is a safe swap for 295/40R20 by the usual ±3% rule: the diameter differs by +1.21%.

20" rim
295/40R20 29.29" · 245/50R20 29.65" · drawn to scale

Side by side

295/40R20245/50R20Difference
Overall diameter29.29"29.65"+0.35" (+1.21%)
Section width295 mm245 mm-50 mm
Sidewall4.65"4.82"+0.18"
Rim20"20"same
Circumference92.0"93.1"+1.1"
Revs per mile689680-8
Ride height——+0.18"
Speedometer reads 60 mph60.060.7+0.7 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.7 mph

With 245/50R20 on a car calibrated for 295/40R20, the speedometer reads 59.3 mph when you're really doing 60, and the odometer under-counts by 1.2%.

Speedo showsActual speed
30 mph30.4 mph
45 mph45.5 mph
60 mph60.7 mph
70 mph70.8 mph
80 mph81.0 mph

Other sizes close to 295/40R20

Questions

Can I replace 295/40R20 with 245/50R20?

245/50R20 is a safe swap for 295/40R20 by the usual ±3% rule: the diameter differs by +1.21%.

What's the difference between 295/40R20 and 245/50R20?

245/50R20 is 0.35" taller and 50 mm narrower; the sidewall is +0.18". At an indicated 60 mph you'd actually be doing 60.7 mph.

Will 245/50R20 fit on 295/40R20 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.