CarSpecsHQ

345/30R19 vs 235/45R19

235/45R19 is a safe swap for 345/30R19 by the usual ±3% rule: the diameter differs by +0.65%.

19" rim
345/30R19 27.15" · 235/45R19 27.33" · drawn to scale

Side by side

345/30R19235/45R19Difference
Overall diameter27.15"27.33"+0.18" (+0.65%)
Section width345 mm235 mm-110 mm
Sidewall4.07"4.16"+0.09"
Rim19"19"same
Circumference85.3"85.8"+0.6"
Revs per mile743738-5
Ride height——+0.09"
Speedometer reads 60 mph60.060.4+0.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.4 mph

With 235/45R19 on a car calibrated for 345/30R19, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.7%.

Speedo showsActual speed
30 mph30.2 mph
45 mph45.3 mph
60 mph60.4 mph
70 mph70.5 mph
80 mph80.5 mph

Other sizes close to 345/30R19

Questions

Can I replace 345/30R19 with 235/45R19?

235/45R19 is a safe swap for 345/30R19 by the usual ±3% rule: the diameter differs by +0.65%.

What's the difference between 345/30R19 and 235/45R19?

235/45R19 is 0.18" taller and 110 mm narrower; the sidewall is +0.09". At an indicated 60 mph you'd actually be doing 60.4 mph.

Will 235/45R19 fit on 345/30R19 wheels?

Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 235 mm tire and the fender clearance.