CarSpecsHQ

275/50R19 vs 255/60R18

255/60R18 is a safe swap for 275/50R19 by the usual ±3% rule: the diameter differs by +0.74%.

19" → 18"
275/50R19 29.83" · 255/60R18 30.05" · drawn to scale

Side by side

275/50R19255/60R18Difference
Overall diameter29.83"30.05"+0.22" (+0.74%)
Section width275 mm255 mm-20 mm
Sidewall5.41"6.02"+0.61"
Rim19"18"-1"
Circumference93.7"94.4"+0.7"
Revs per mile676671-5
Ride height——+0.11"
Speedometer reads 60 mph60.060.4+0.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.4 mph

With 255/60R18 on a car calibrated for 275/50R19, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.7%.

Speedo showsActual speed
30 mph30.2 mph
45 mph45.3 mph
60 mph60.4 mph
70 mph70.5 mph
80 mph80.6 mph

Other sizes close to 275/50R19

Questions

Can I replace 275/50R19 with 255/60R18?

255/60R18 is a safe swap for 275/50R19 by the usual ±3% rule: the diameter differs by +0.74%.

What's the difference between 275/50R19 and 255/60R18?

255/60R18 is 0.22" taller and 20 mm narrower; the sidewall is +0.61". At an indicated 60 mph you'd actually be doing 60.4 mph.

Will 255/60R18 fit on 275/50R19 wheels?

No — 275/50R19 needs a 19" wheel and 255/60R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.