CarSpecsHQ

255/45R19 vs 275/45R19

275/45R19 is a safe swap for 255/45R19 by the usual ±3% rule: the diameter differs by +2.53%.

19" rim
255/45R19 28.04" · 275/45R19 28.74" · drawn to scale

Side by side

255/45R19275/45R19Difference
Overall diameter28.04"28.74"+0.71" (+2.53%)
Section width255 mm275 mm+20 mm
Sidewall4.52"4.87"+0.35"
Rim19"19"same
Circumference88.1"90.3"+2.2"
Revs per mile719702-18
Ride height——+0.35"
Speedometer reads 60 mph60.061.5+1.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.5 mph

With 275/45R19 on a car calibrated for 255/45R19, the speedometer reads 58.5 mph when you're really doing 60, and the odometer under-counts by 2.5%.

Speedo showsActual speed
30 mph30.8 mph
45 mph46.1 mph
60 mph61.5 mph
70 mph71.8 mph
80 mph82.0 mph

Other sizes close to 255/45R19

Questions

Can I replace 255/45R19 with 275/45R19?

275/45R19 is a safe swap for 255/45R19 by the usual ±3% rule: the diameter differs by +2.53%.

What's the difference between 255/45R19 and 275/45R19?

275/45R19 is 0.71" taller and 20 mm wider; the sidewall is +0.35". At an indicated 60 mph you'd actually be doing 61.5 mph.

Will 275/45R19 fit on 255/45R19 wheels?

Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.