CarSpecsHQ

285/40R19 vs 225/55R19

225/55R19 is a safe swap for 285/40R19 by the usual ±3% rule: the diameter differs by +2.74%.

19" rim
285/40R19 27.98" · 225/55R19 28.74" · drawn to scale

Side by side

285/40R19225/55R19Difference
Overall diameter27.98"28.74"+0.77" (+2.74%)
Section width285 mm225 mm-60 mm
Sidewall4.49"4.87"+0.38"
Rim19"19"same
Circumference87.9"90.3"+2.4"
Revs per mile721702-19
Ride height——+0.38"
Speedometer reads 60 mph60.061.6+1.6 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.6 mph

With 225/55R19 on a car calibrated for 285/40R19, the speedometer reads 58.4 mph when you're really doing 60, and the odometer under-counts by 2.7%.

Speedo showsActual speed
30 mph30.8 mph
45 mph46.2 mph
60 mph61.6 mph
70 mph71.9 mph
80 mph82.2 mph

Other sizes close to 285/40R19

Questions

Can I replace 285/40R19 with 225/55R19?

225/55R19 is a safe swap for 285/40R19 by the usual ±3% rule: the diameter differs by +2.74%.

What's the difference between 285/40R19 and 225/55R19?

225/55R19 is 0.77" taller and 60 mm narrower; the sidewall is +0.38". At an indicated 60 mph you'd actually be doing 61.6 mph.

Will 225/55R19 fit on 285/40R19 wheels?

Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 225 mm tire and the fender clearance.