CarSpecsHQ

285/35R19 vs 285/40R19

285/40R19 is outside the ±3% rule as a replacement for 285/35R19: the diameter differs by +4.18%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

19" rim
285/35R19 26.85" · 285/40R19 27.98" · drawn to scale

Side by side

285/35R19285/40R19Difference
Overall diameter26.85"27.98"+1.12" (+4.18%)
Section width285 mm285 mm0 mm
Sidewall3.93"4.49"+0.56"
Rim19"19"same
Circumference84.4"87.9"+3.5"
Revs per mile751721-30
Ride height——+0.56"
Speedometer reads 60 mph60.062.5+2.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.5 mph

With 285/40R19 on a car calibrated for 285/35R19, the speedometer reads 57.6 mph when you're really doing 60, and the odometer under-counts by 4.2%.

Speedo showsActual speed
30 mph31.3 mph
45 mph46.9 mph
60 mph62.5 mph
70 mph72.9 mph
80 mph83.3 mph

Other sizes close to 285/35R19

Questions

Can I replace 285/35R19 with 285/40R19?

285/40R19 is outside the ±3% rule as a replacement for 285/35R19: the diameter differs by +4.18%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 285/35R19 and 285/40R19?

285/40R19 is 1.12" taller and 0 mm wider; the sidewall is +0.56". At an indicated 60 mph you'd actually be doing 62.5 mph.

Will 285/40R19 fit on 285/35R19 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.