CarSpecsHQ

285/30R19 vs 325/30R19

325/30R19 is outside the ±3% rule as a replacement for 285/30R19: the diameter differs by +3.67%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

19" rim
285/30R19 25.73" · 325/30R19 26.68" · drawn to scale

Side by side

285/30R19325/30R19Difference
Overall diameter25.73"26.68"+0.94" (+3.67%)
Section width285 mm325 mm+40 mm
Sidewall3.37"3.84"+0.47"
Rim19"19"same
Circumference80.8"83.8"+3.0"
Revs per mile784756-28
Ride height——+0.47"
Speedometer reads 60 mph60.062.2+2.2 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.2 mph

With 325/30R19 on a car calibrated for 285/30R19, the speedometer reads 57.9 mph when you're really doing 60, and the odometer under-counts by 3.7%.

Speedo showsActual speed
30 mph31.1 mph
45 mph46.7 mph
60 mph62.2 mph
70 mph72.6 mph
80 mph82.9 mph

Other sizes close to 285/30R19

Questions

Can I replace 285/30R19 with 325/30R19?

325/30R19 is outside the ±3% rule as a replacement for 285/30R19: the diameter differs by +3.67%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 285/30R19 and 325/30R19?

325/30R19 is 0.94" taller and 40 mm wider; the sidewall is +0.47". At an indicated 60 mph you'd actually be doing 62.2 mph.

Will 325/30R19 fit on 285/30R19 wheels?

Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 325 mm tire and the fender clearance.