CarSpecsHQ

245/35R19 vs 235/40R19

235/40R19 is a safe swap for 245/35R19 by the usual ±3% rule: the diameter differs by +2.52%.

19" rim
245/35R19 25.75" · 235/40R19 26.40" · drawn to scale

Side by side

245/35R19235/40R19Difference
Overall diameter25.75"26.40"+0.65" (+2.52%)
Section width245 mm235 mm-10 mm
Sidewall3.38"3.70"+0.32"
Rim19"19"same
Circumference80.9"82.9"+2.0"
Revs per mile783764-19
Ride height——+0.32"
Speedometer reads 60 mph60.061.5+1.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.5 mph

With 235/40R19 on a car calibrated for 245/35R19, the speedometer reads 58.5 mph when you're really doing 60, and the odometer under-counts by 2.5%.

Speedo showsActual speed
30 mph30.8 mph
45 mph46.1 mph
60 mph61.5 mph
70 mph71.8 mph
80 mph82.0 mph

Other sizes close to 245/35R19

Questions

Can I replace 245/35R19 with 235/40R19?

235/40R19 is a safe swap for 245/35R19 by the usual ±3% rule: the diameter differs by +2.52%.

What's the difference between 245/35R19 and 235/40R19?

235/40R19 is 0.65" taller and 10 mm narrower; the sidewall is +0.32". At an indicated 60 mph you'd actually be doing 61.5 mph.

Will 235/40R19 fit on 245/35R19 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.