CarSpecsHQ

295/40R20 vs 275/50R20

275/50R20 is outside the ±3% rule as a replacement for 295/40R20: the diameter differs by +5.24%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

20" rim
295/40R20 29.29" · 275/50R20 30.83" · drawn to scale

Side by side

295/40R20275/50R20Difference
Overall diameter29.29"30.83"+1.54" (+5.24%)
Section width295 mm275 mm-20 mm
Sidewall4.65"5.41"+0.77"
Rim20"20"same
Circumference92.0"96.8"+4.8"
Revs per mile689654-34
Ride height——+0.77"
Speedometer reads 60 mph60.063.1+3.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 63.1 mph

With 275/50R20 on a car calibrated for 295/40R20, the speedometer reads 57.0 mph when you're really doing 60, and the odometer under-counts by 5.2%.

Speedo showsActual speed
30 mph31.6 mph
45 mph47.4 mph
60 mph63.1 mph
70 mph73.7 mph
80 mph84.2 mph

Other sizes close to 295/40R20

Questions

Can I replace 295/40R20 with 275/50R20?

275/50R20 is outside the ±3% rule as a replacement for 295/40R20: the diameter differs by +5.24%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 295/40R20 and 275/50R20?

275/50R20 is 1.54" taller and 20 mm narrower; the sidewall is +0.77". At an indicated 60 mph you'd actually be doing 63.1 mph.

Will 275/50R20 fit on 295/40R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.