CarSpecsHQ

275/35R19 vs 345/30R19

345/30R19 is a safe swap for 275/35R19 by the usual ±3% rule: the diameter differs by +2.15%.

19" rim
275/35R19 26.58" · 345/30R19 27.15" · drawn to scale

Side by side

275/35R19345/30R19Difference
Overall diameter26.58"27.15"+0.57" (+2.15%)
Section width275 mm345 mm+70 mm
Sidewall3.79"4.07"+0.29"
Rim19"19"same
Circumference83.5"85.3"+1.8"
Revs per mile759743-16
Ride height——+0.29"
Speedometer reads 60 mph60.061.3+1.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.3 mph

With 345/30R19 on a car calibrated for 275/35R19, the speedometer reads 58.7 mph when you're really doing 60, and the odometer under-counts by 2.1%.

Speedo showsActual speed
30 mph30.6 mph
45 mph46.0 mph
60 mph61.3 mph
70 mph71.5 mph
80 mph81.7 mph

Other sizes close to 275/35R19

Questions

Can I replace 275/35R19 with 345/30R19?

345/30R19 is a safe swap for 275/35R19 by the usual ±3% rule: the diameter differs by +2.15%.

What's the difference between 275/35R19 and 345/30R19?

345/30R19 is 0.57" taller and 70 mm wider; the sidewall is +0.29". At an indicated 60 mph you'd actually be doing 61.3 mph.

Will 345/30R19 fit on 275/35R19 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.