CarSpecsHQ

245/45R17 vs 235/50R17

235/50R17 is a safe swap for 245/45R17 by the usual ±3% rule: the diameter differs by +2.22%.

17" rim
245/45R17 25.68" · 235/50R17 26.25" · drawn to scale

Side by side

245/45R17235/50R17Difference
Overall diameter25.68"26.25"+0.57" (+2.22%)
Section width245 mm235 mm-10 mm
Sidewall4.34"4.63"+0.29"
Rim17"17"same
Circumference80.7"82.5"+1.8"
Revs per mile785768-17
Ride height——+0.29"
Speedometer reads 60 mph60.061.3+1.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.3 mph

With 235/50R17 on a car calibrated for 245/45R17, the speedometer reads 58.7 mph when you're really doing 60, and the odometer under-counts by 2.2%.

Speedo showsActual speed
30 mph30.7 mph
45 mph46.0 mph
60 mph61.3 mph
70 mph71.6 mph
80 mph81.8 mph

Other sizes close to 245/45R17

Questions

Can I replace 245/45R17 with 235/50R17?

235/50R17 is a safe swap for 245/45R17 by the usual ±3% rule: the diameter differs by +2.22%.

What's the difference between 245/45R17 and 235/50R17?

235/50R17 is 0.57" taller and 10 mm narrower; the sidewall is +0.29". At an indicated 60 mph you'd actually be doing 61.3 mph.

Will 235/50R17 fit on 245/45R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 235 mm tire and the fender clearance.