CarSpecsHQ

225/45R19 vs 255/45R19

255/45R19 is outside the ±3% rule as a replacement for 225/45R19: the diameter differs by +3.94%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

19" rim
225/45R19 26.97" · 255/45R19 28.04" · drawn to scale

Side by side

225/45R19255/45R19Difference
Overall diameter26.97"28.04"+1.06" (+3.94%)
Section width225 mm255 mm+30 mm
Sidewall3.99"4.52"+0.53"
Rim19"19"same
Circumference84.7"88.1"+3.3"
Revs per mile748719-28
Ride height——+0.53"
Speedometer reads 60 mph60.062.4+2.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.4 mph

With 255/45R19 on a car calibrated for 225/45R19, the speedometer reads 57.7 mph when you're really doing 60, and the odometer under-counts by 3.9%.

Speedo showsActual speed
30 mph31.2 mph
45 mph46.8 mph
60 mph62.4 mph
70 mph72.8 mph
80 mph83.2 mph

Other sizes close to 225/45R19

Questions

Can I replace 225/45R19 with 255/45R19?

255/45R19 is outside the ±3% rule as a replacement for 225/45R19: the diameter differs by +3.94%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 225/45R19 and 255/45R19?

255/45R19 is 1.06" taller and 30 mm wider; the sidewall is +0.53". At an indicated 60 mph you'd actually be doing 62.4 mph.

Will 255/45R19 fit on 225/45R19 wheels?

Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 255 mm tire and the fender clearance.