CarSpecsHQ

185/60R15 vs 225/50R15

225/50R15 is a safe swap for 185/60R15 by the usual ±3% rule: the diameter differs by +0.50%.

15" rim
185/60R15 23.74" · 225/50R15 23.86" · drawn to scale

Side by side

185/60R15225/50R15Difference
Overall diameter23.74"23.86"+0.12" (+0.50%)
Section width185 mm225 mm+40 mm
Sidewall4.37"4.43"+0.06"
Rim15"15"same
Circumference74.6"75.0"+0.4"
Revs per mile850845-4
Ride height——+0.06"
Speedometer reads 60 mph60.060.3+0.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.3 mph

With 225/50R15 on a car calibrated for 185/60R15, the speedometer reads 59.7 mph when you're really doing 60, and the odometer under-counts by 0.5%.

Speedo showsActual speed
30 mph30.1 mph
45 mph45.2 mph
60 mph60.3 mph
70 mph70.3 mph
80 mph80.4 mph

Other sizes close to 185/60R15

Questions

Can I replace 185/60R15 with 225/50R15?

225/50R15 is a safe swap for 185/60R15 by the usual ±3% rule: the diameter differs by +0.50%.

What's the difference between 185/60R15 and 225/50R15?

225/50R15 is 0.12" taller and 40 mm wider; the sidewall is +0.06". At an indicated 60 mph you'd actually be doing 60.3 mph.

Will 225/50R15 fit on 185/60R15 wheels?

Both use a 15" rim, so the wheel diameter matches; check the wheel's width range for a 225 mm tire and the fender clearance.