CarSpecsHQ

325/30R19 vs 345/30R19

345/30R19 is a safe swap for 325/30R19 by the usual ±3% rule: the diameter differs by +1.77%.

19" rim
325/30R19 26.68" · 345/30R19 27.15" · drawn to scale

Side by side

325/30R19345/30R19Difference
Overall diameter26.68"27.15"+0.47" (+1.77%)
Section width325 mm345 mm+20 mm
Sidewall3.84"4.07"+0.24"
Rim19"19"same
Circumference83.8"85.3"+1.5"
Revs per mile756743-13
Ride height——+0.24"
Speedometer reads 60 mph60.061.1+1.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.1 mph

With 345/30R19 on a car calibrated for 325/30R19, the speedometer reads 59.0 mph when you're really doing 60, and the odometer under-counts by 1.8%.

Speedo showsActual speed
30 mph30.5 mph
45 mph45.8 mph
60 mph61.1 mph
70 mph71.2 mph
80 mph81.4 mph

Other sizes close to 325/30R19

Questions

Can I replace 325/30R19 with 345/30R19?

345/30R19 is a safe swap for 325/30R19 by the usual ±3% rule: the diameter differs by +1.77%.

What's the difference between 325/30R19 and 345/30R19?

345/30R19 is 0.47" taller and 20 mm wider; the sidewall is +0.24". At an indicated 60 mph you'd actually be doing 61.1 mph.

Will 345/30R19 fit on 325/30R19 wheels?

Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 345 mm tire and the fender clearance.