CarSpecsHQ

215/60R17 vs 215/55R18

215/55R18 is a safe swap for 215/60R17 by the usual ±3% rule: the diameter differs by +0.57%.

17" → 18"
215/60R17 27.16" · 215/55R18 27.31" · drawn to scale

Side by side

215/60R17215/55R18Difference
Overall diameter27.16"27.31"+0.15" (+0.57%)
Section width215 mm215 mm0 mm
Sidewall5.08"4.66"-0.42"
Rim17"18"+1"
Circumference85.3"85.8"+0.5"
Revs per mile743738-4
Ride height——+0.08"
Speedometer reads 60 mph60.060.3+0.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.3 mph

With 215/55R18 on a car calibrated for 215/60R17, the speedometer reads 59.7 mph when you're really doing 60, and the odometer under-counts by 0.6%.

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

Other sizes close to 215/60R17

Questions

Can I replace 215/60R17 with 215/55R18?

215/55R18 is a safe swap for 215/60R17 by the usual ±3% rule: the diameter differs by +0.57%.

What's the difference between 215/60R17 and 215/55R18?

215/55R18 is 0.15" taller and 0 mm wider; the sidewall is -0.42". At an indicated 60 mph you'd actually be doing 60.3 mph.

Will 215/55R18 fit on 215/60R17 wheels?

No — 215/60R17 needs a 17" wheel and 215/55R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.