CarSpecsHQ

255/50R20 vs 295/45R20

295/45R20 is a safe swap for 255/50R20 by the usual ±3% rule: the diameter differs by +1.38%.

20" rim
255/50R20 30.04" · 295/45R20 30.45" · drawn to scale

Side by side

255/50R20295/45R20Difference
Overall diameter30.04"30.45"+0.41" (+1.38%)
Section width255 mm295 mm+40 mm
Sidewall5.02"5.23"+0.21"
Rim20"20"same
Circumference94.4"95.7"+1.3"
Revs per mile671662-9
Ride height——+0.21"
Speedometer reads 60 mph60.060.8+0.8 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.8 mph

With 295/45R20 on a car calibrated for 255/50R20, the speedometer reads 59.2 mph when you're really doing 60, and the odometer under-counts by 1.4%.

Speedo showsActual speed
30 mph30.4 mph
45 mph45.6 mph
60 mph60.8 mph
70 mph71.0 mph
80 mph81.1 mph

Other sizes close to 255/50R20

Questions

Can I replace 255/50R20 with 295/45R20?

295/45R20 is a safe swap for 255/50R20 by the usual ±3% rule: the diameter differs by +1.38%.

What's the difference between 255/50R20 and 295/45R20?

295/45R20 is 0.41" taller and 40 mm wider; the sidewall is +0.21". At an indicated 60 mph you'd actually be doing 60.8 mph.

Will 295/45R20 fit on 255/50R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 295 mm tire and the fender clearance.