CarSpecsHQ

265/50R20 vs 275/55R20

275/55R20 is outside the ±3% rule as a replacement for 265/50R20: the diameter differs by +4.85%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

20" rim
265/50R20 30.43" · 275/55R20 31.91" · drawn to scale

Side by side

265/50R20275/55R20Difference
Overall diameter30.43"31.91"+1.48" (+4.85%)
Section width265 mm275 mm+10 mm
Sidewall5.22"5.95"+0.74"
Rim20"20"same
Circumference95.6"100.2"+4.6"
Revs per mile663632-31
Ride height——+0.74"
Speedometer reads 60 mph60.062.9+2.9 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.9 mph

With 275/55R20 on a car calibrated for 265/50R20, the speedometer reads 57.2 mph when you're really doing 60, and the odometer under-counts by 4.9%.

Speedo showsActual speed
30 mph31.5 mph
45 mph47.2 mph
60 mph62.9 mph
70 mph73.4 mph
80 mph83.9 mph

Other sizes close to 265/50R20

Questions

Can I replace 265/50R20 with 275/55R20?

275/55R20 is outside the ±3% rule as a replacement for 265/50R20: the diameter differs by +4.85%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 265/50R20 and 275/55R20?

275/55R20 is 1.48" taller and 10 mm wider; the sidewall is +0.74". At an indicated 60 mph you'd actually be doing 62.9 mph.

Will 275/55R20 fit on 265/50R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.