CarSpecsHQ

275/50R20 vs 255/60R19

255/60R19 is a safe swap for 275/50R20 by the usual ±3% rule: the diameter differs by +0.72%.

20" → 19"
275/50R20 30.83" · 255/60R19 31.05" · drawn to scale

Side by side

275/50R20255/60R19Difference
Overall diameter30.83"31.05"+0.22" (+0.72%)
Section width275 mm255 mm-20 mm
Sidewall5.41"6.02"+0.61"
Rim20"19"-1"
Circumference96.8"97.5"+0.7"
Revs per mile654650-5
Ride height——+0.11"
Speedometer reads 60 mph60.060.4+0.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.4 mph

With 255/60R19 on a car calibrated for 275/50R20, 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 275/50R20

Questions

Can I replace 275/50R20 with 255/60R19?

255/60R19 is a safe swap for 275/50R20 by the usual ±3% rule: the diameter differs by +0.72%.

What's the difference between 275/50R20 and 255/60R19?

255/60R19 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 255/60R19 fit on 275/50R20 wheels?

No — 275/50R20 needs a 20" wheel and 255/60R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.