CarSpecsHQ

225/40R19 vs 235/45R19

235/45R19 is outside the ±3% rule as a replacement for 225/40R19: the diameter differs by +4.75%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

19" rim
225/40R19 26.09" · 235/45R19 27.33" · drawn to scale

Side by side

225/40R19235/45R19Difference
Overall diameter26.09"27.33"+1.24" (+4.75%)
Section width225 mm235 mm+10 mm
Sidewall3.54"4.16"+0.62"
Rim19"19"same
Circumference82.0"85.8"+3.9"
Revs per mile773738-35
Ride height——+0.62"
Speedometer reads 60 mph60.062.9+2.9 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.9 mph

With 235/45R19 on a car calibrated for 225/40R19, the speedometer reads 57.3 mph when you're really doing 60, and the odometer under-counts by 4.8%.

Speedo showsActual speed
30 mph31.4 mph
45 mph47.1 mph
60 mph62.9 mph
70 mph73.3 mph
80 mph83.8 mph

Other sizes close to 225/40R19

Questions

Can I replace 225/40R19 with 235/45R19?

235/45R19 is outside the ±3% rule as a replacement for 225/40R19: the diameter differs by +4.75%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 225/40R19 and 235/45R19?

235/45R19 is 1.24" taller and 10 mm wider; the sidewall is +0.62". At an indicated 60 mph you'd actually be doing 62.9 mph.

Will 235/45R19 fit on 225/40R19 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.