CarSpecsHQ

255/30R19 vs 235/35R19

235/35R19 is a safe swap for 255/30R19 by the usual ±3% rule: the diameter differs by +1.81%.

19" rim
255/30R19 25.02" · 235/35R19 25.48" · drawn to scale

Side by side

255/30R19235/35R19Difference
Overall diameter25.02"25.48"+0.45" (+1.81%)
Section width255 mm235 mm-20 mm
Sidewall3.01"3.24"+0.23"
Rim19"19"same
Circumference78.6"80.0"+1.4"
Revs per mile806792-14
Ride height——+0.23"
Speedometer reads 60 mph60.061.1+1.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.1 mph

With 235/35R19 on a car calibrated for 255/30R19, the speedometer reads 58.9 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 mph71.3 mph
80 mph81.4 mph

Other sizes close to 255/30R19

Questions

Can I replace 255/30R19 with 235/35R19?

235/35R19 is a safe swap for 255/30R19 by the usual ±3% rule: the diameter differs by +1.81%.

What's the difference between 255/30R19 and 235/35R19?

235/35R19 is 0.45" taller and 20 mm narrower; the sidewall is +0.23". At an indicated 60 mph you'd actually be doing 61.1 mph.

Will 235/35R19 fit on 255/30R19 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.