CarSpecsHQ

255/30R19 vs 285/30R19

285/30R19 is a safe swap for 255/30R19 by the usual ±3% rule: the diameter differs by +2.83%.

19" rim
255/30R19 25.02" · 285/30R19 25.73" · drawn to scale

Side by side

255/30R19285/30R19Difference
Overall diameter25.02"25.73"+0.71" (+2.83%)
Section width255 mm285 mm+30 mm
Sidewall3.01"3.37"+0.35"
Rim19"19"same
Circumference78.6"80.8"+2.2"
Revs per mile806784-22
Ride height——+0.35"
Speedometer reads 60 mph60.061.7+1.7 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.7 mph

With 285/30R19 on a car calibrated for 255/30R19, the speedometer reads 58.3 mph when you're really doing 60, and the odometer under-counts by 2.8%.

Speedo showsActual speed
30 mph30.8 mph
45 mph46.3 mph
60 mph61.7 mph
70 mph72.0 mph
80 mph82.3 mph

Other sizes close to 255/30R19

Questions

Can I replace 255/30R19 with 285/30R19?

285/30R19 is a safe swap for 255/30R19 by the usual ±3% rule: the diameter differs by +2.83%.

What's the difference between 255/30R19 and 285/30R19?

285/30R19 is 0.71" taller and 30 mm wider; the sidewall is +0.35". At an indicated 60 mph you'd actually be doing 61.7 mph.

Will 285/30R19 fit on 255/30R19 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.