CarSpecsHQ

255/50R19 vs 285/45R19

285/45R19 is a safe swap for 255/50R19 by the usual ±3% rule: the diameter differs by +0.20%.

19" rim
255/50R19 29.04" · 285/45R19 29.10" · drawn to scale

Side by side

255/50R19285/45R19Difference
Overall diameter29.04"29.10"+0.06" (+0.20%)
Section width255 mm285 mm+30 mm
Sidewall5.02"5.05"+0.03"
Rim19"19"same
Circumference91.2"91.4"+0.2"
Revs per mile695693-1
Ride height——+0.03"
Speedometer reads 60 mph60.060.1+0.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.1 mph

With 285/45R19 on a car calibrated for 255/50R19, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.2%.

Speedo showsActual speed
30 mph30.1 mph
45 mph45.1 mph
60 mph60.1 mph
70 mph70.1 mph
80 mph80.2 mph

Other sizes close to 255/50R19

Questions

Can I replace 255/50R19 with 285/45R19?

285/45R19 is a safe swap for 255/50R19 by the usual ±3% rule: the diameter differs by +0.20%.

What's the difference between 255/50R19 and 285/45R19?

285/45R19 is 0.06" taller and 30 mm wider; the sidewall is +0.03". At an indicated 60 mph you'd actually be doing 60.1 mph.

Will 285/45R19 fit on 255/50R19 wheels?

Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 285 mm tire and the fender clearance.