CarSpecsHQ

235/35R19 vs 315/30R19

315/30R19 is outside the ±3% rule as a replacement for 235/35R19: the diameter differs by +3.79%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

19" rim
235/35R19 25.48" · 315/30R19 26.44" · drawn to scale

Side by side

235/35R19315/30R19Difference
Overall diameter25.48"26.44"+0.96" (+3.79%)
Section width235 mm315 mm+80 mm
Sidewall3.24"3.72"+0.48"
Rim19"19"same
Circumference80.0"83.1"+3.0"
Revs per mile792763-29
Ride height——+0.48"
Speedometer reads 60 mph60.062.3+2.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.3 mph

With 315/30R19 on a car calibrated for 235/35R19, the speedometer reads 57.8 mph when you're really doing 60, and the odometer under-counts by 3.8%.

Speedo showsActual speed
30 mph31.1 mph
45 mph46.7 mph
60 mph62.3 mph
70 mph72.7 mph
80 mph83.0 mph

Other sizes close to 235/35R19

Questions

Can I replace 235/35R19 with 315/30R19?

315/30R19 is outside the ±3% rule as a replacement for 235/35R19: the diameter differs by +3.79%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 235/35R19 and 315/30R19?

315/30R19 is 0.96" taller and 80 mm wider; the sidewall is +0.48". At an indicated 60 mph you'd actually be doing 62.3 mph.

Will 315/30R19 fit on 235/35R19 wheels?

Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 315 mm tire and the fender clearance.