CarSpecsHQ

315/30R19 vs 325/30R19

325/30R19 is a safe swap for 315/30R19 by the usual ±3% rule: the diameter differs by +0.89%.

19" rim
315/30R19 26.44" · 325/30R19 26.68" · drawn to scale

Side by side

315/30R19325/30R19Difference
Overall diameter26.44"26.68"+0.24" (+0.89%)
Section width315 mm325 mm+10 mm
Sidewall3.72"3.84"+0.12"
Rim19"19"same
Circumference83.1"83.8"+0.7"
Revs per mile763756-7
Ride height——+0.12"
Speedometer reads 60 mph60.060.5+0.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.5 mph

With 325/30R19 on a car calibrated for 315/30R19, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.9%.

Speedo showsActual speed
30 mph30.3 mph
45 mph45.4 mph
60 mph60.5 mph
70 mph70.6 mph
80 mph80.7 mph

Other sizes close to 315/30R19

Questions

Can I replace 315/30R19 with 325/30R19?

325/30R19 is a safe swap for 315/30R19 by the usual ±3% rule: the diameter differs by +0.89%.

What's the difference between 315/30R19 and 325/30R19?

325/30R19 is 0.24" taller and 10 mm wider; the sidewall is +0.12". At an indicated 60 mph you'd actually be doing 60.5 mph.

Will 325/30R19 fit on 315/30R19 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.