CarSpecsHQ

225/50R17 vs 335/30R18

335/30R18 is a safe swap for 225/50R17 by the usual ±3% rule: the diameter differs by +0.21%.

17" → 18"
225/50R17 25.86" · 335/30R18 25.91" · drawn to scale

Side by side

225/50R17335/30R18Difference
Overall diameter25.86"25.91"+0.06" (+0.21%)
Section width225 mm335 mm+110 mm
Sidewall4.43"3.96"-0.47"
Rim17"18"+1"
Circumference81.2"81.4"+0.2"
Revs per mile780778-2
Ride height——+0.03"
Speedometer reads 60 mph60.060.1+0.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.1 mph

With 335/30R18 on a car calibrated for 225/50R17, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.2%.

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

Other sizes close to 225/50R17

Questions

Can I replace 225/50R17 with 335/30R18?

335/30R18 is a safe swap for 225/50R17 by the usual ±3% rule: the diameter differs by +0.21%.

What's the difference between 225/50R17 and 335/30R18?

335/30R18 is 0.06" taller and 110 mm wider; the sidewall is -0.47". At an indicated 60 mph you'd actually be doing 60.1 mph.

Will 335/30R18 fit on 225/50R17 wheels?

No — 225/50R17 needs a 17" wheel and 335/30R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.