CarSpecsHQ

245/35R19 vs 325/30R19

325/30R19 is outside the ±3% rule as a replacement for 245/35R19: the diameter differs by +3.59%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

19" rim
245/35R19 25.75" · 325/30R19 26.68" · drawn to scale

Side by side

245/35R19325/30R19Difference
Overall diameter25.75"26.68"+0.93" (+3.59%)
Section width245 mm325 mm+80 mm
Sidewall3.38"3.84"+0.46"
Rim19"19"same
Circumference80.9"83.8"+2.9"
Revs per mile783756-27
Ride height——+0.46"
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 245/35R19, the speedometer reads 57.9 mph when you're really doing 60, and the odometer under-counts by 3.6%.

Speedo showsActual speed
30 mph31.1 mph
45 mph46.6 mph
60 mph62.2 mph
70 mph72.5 mph
80 mph82.9 mph

Other sizes close to 245/35R19

Questions

Can I replace 245/35R19 with 325/30R19?

325/30R19 is outside the ±3% rule as a replacement for 245/35R19: the diameter differs by +3.59%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 245/35R19 and 325/30R19?

325/30R19 is 0.93" taller and 80 mm wider; the sidewall is +0.46". At an indicated 60 mph you'd actually be doing 62.2 mph.

Will 325/30R19 fit on 245/35R19 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.