CarSpecsHQ

275/30R19 vs 325/30R19

325/30R19 is outside the ±3% rule as a replacement for 275/30R19: the diameter differs by +4.63%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

19" rim
275/30R19 25.50" · 325/30R19 26.68" · drawn to scale

Side by side

275/30R19325/30R19Difference
Overall diameter25.50"26.68"+1.18" (+4.63%)
Section width275 mm325 mm+50 mm
Sidewall3.25"3.84"+0.59"
Rim19"19"same
Circumference80.1"83.8"+3.7"
Revs per mile791756-35
Ride height——+0.59"
Speedometer reads 60 mph60.062.8+2.8 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.8 mph

With 325/30R19 on a car calibrated for 275/30R19, the speedometer reads 57.3 mph when you're really doing 60, and the odometer under-counts by 4.6%.

Speedo showsActual speed
30 mph31.4 mph
45 mph47.1 mph
60 mph62.8 mph
70 mph73.2 mph
80 mph83.7 mph

Other sizes close to 275/30R19

Questions

Can I replace 275/30R19 with 325/30R19?

325/30R19 is outside the ±3% rule as a replacement for 275/30R19: the diameter differs by +4.63%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 275/30R19 and 325/30R19?

325/30R19 is 1.18" taller and 50 mm wider; the sidewall is +0.59". At an indicated 60 mph you'd actually be doing 62.8 mph.

Will 325/30R19 fit on 275/30R19 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.