CarSpecsHQ

255/55R19 vs 255/60R18

255/60R18 is a safe swap for 255/55R19 by the usual ±3% rule: the diameter differs by +0.01%.

19" → 18"
255/55R19 30.04" · 255/60R18 30.05" · drawn to scale

Side by side

255/55R19255/60R18Difference
Overall diameter30.04"30.05"+0.00" (+0.01%)
Section width255 mm255 mm0 mm
Sidewall5.52"6.02"+0.50"
Rim19"18"-1"
Circumference94.4"94.4"+0.0"
Revs per mile671671-0
Ride height——+0.00"
Speedometer reads 60 mph60.060.0+0.0 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.0 mph

With 255/60R18 on a car calibrated for 255/55R19, the speedometer reads 60.0 mph when you're really doing 60, and the odometer under-counts by 0.0%.

Speedo showsActual speed
30 mph30.0 mph
45 mph45.0 mph
60 mph60.0 mph
70 mph70.0 mph
80 mph80.0 mph

Other sizes close to 255/55R19

Questions

Can I replace 255/55R19 with 255/60R18?

255/60R18 is a safe swap for 255/55R19 by the usual ±3% rule: the diameter differs by +0.01%.

What's the difference between 255/55R19 and 255/60R18?

255/60R18 is 0.00" taller and 0 mm wider; the sidewall is +0.50". At an indicated 60 mph you'd actually be doing 60.0 mph.

Will 255/60R18 fit on 255/55R19 wheels?

No — 255/55R19 needs a 19" wheel and 255/60R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.