CarSpecsHQ

225/50R17 vs 255/45R17

255/45R17 is a safe swap for 225/50R17 by the usual ±3% rule: the diameter differs by +0.69%.

17" rim
225/50R17 25.86" · 255/45R17 26.04" · drawn to scale

Side by side

225/50R17255/45R17Difference
Overall diameter25.86"26.04"+0.18" (+0.69%)
Section width225 mm255 mm+30 mm
Sidewall4.43"4.52"+0.09"
Rim17"17"same
Circumference81.2"81.8"+0.6"
Revs per mile780775-5
Ride height——+0.09"
Speedometer reads 60 mph60.060.4+0.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.4 mph

With 255/45R17 on a car calibrated for 225/50R17, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.7%.

Speedo showsActual speed
30 mph30.2 mph
45 mph45.3 mph
60 mph60.4 mph
70 mph70.5 mph
80 mph80.5 mph

Other sizes close to 225/50R17

Questions

Can I replace 225/50R17 with 255/45R17?

255/45R17 is a safe swap for 225/50R17 by the usual ±3% rule: the diameter differs by +0.69%.

What's the difference between 225/50R17 and 255/45R17?

255/45R17 is 0.18" taller and 30 mm wider; the sidewall is +0.09". At an indicated 60 mph you'd actually be doing 60.4 mph.

Will 255/45R17 fit on 225/50R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 255 mm tire and the fender clearance.