CarSpecsHQ

295/45R20 vs 285/50R20

285/50R20 is a safe swap for 295/45R20 by the usual ±3% rule: the diameter differs by +2.52%.

20" rim
295/45R20 30.45" · 285/50R20 31.22" · drawn to scale

Side by side

295/45R20285/50R20Difference
Overall diameter30.45"31.22"+0.77" (+2.52%)
Section width295 mm285 mm-10 mm
Sidewall5.23"5.61"+0.38"
Rim20"20"same
Circumference95.7"98.1"+2.4"
Revs per mile662646-16
Ride height——+0.38"
Speedometer reads 60 mph60.061.5+1.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.5 mph

With 285/50R20 on a car calibrated for 295/45R20, the speedometer reads 58.5 mph when you're really doing 60, and the odometer under-counts by 2.5%.

Speedo showsActual speed
30 mph30.8 mph
45 mph46.1 mph
60 mph61.5 mph
70 mph71.8 mph
80 mph82.0 mph

Other sizes close to 295/45R20

Questions

Can I replace 295/45R20 with 285/50R20?

285/50R20 is a safe swap for 295/45R20 by the usual ±3% rule: the diameter differs by +2.52%.

What's the difference between 295/45R20 and 285/50R20?

285/50R20 is 0.77" taller and 10 mm narrower; the sidewall is +0.38". At an indicated 60 mph you'd actually be doing 61.5 mph.

Will 285/50R20 fit on 295/45R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 285 mm tire and the fender clearance.