CarSpecsHQ

235/70R15 vs 235/75R15

235/75R15 is outside the ±3% rule as a replacement for 235/70R15: the diameter differs by +3.31%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

15" rim
235/70R15 27.95" · 235/75R15 28.88" · drawn to scale

Side by side

235/70R15235/75R15Difference
Overall diameter27.95"28.88"+0.93" (+3.31%)
Section width235 mm235 mm0 mm
Sidewall6.48"6.94"+0.46"
Rim15"15"same
Circumference87.8"90.7"+2.9"
Revs per mile722698-23
Ride height——+0.46"
Speedometer reads 60 mph60.062.0+2.0 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.0 mph

With 235/75R15 on a car calibrated for 235/70R15, the speedometer reads 58.1 mph when you're really doing 60, and the odometer under-counts by 3.3%.

Speedo showsActual speed
30 mph31.0 mph
45 mph46.5 mph
60 mph62.0 mph
70 mph72.3 mph
80 mph82.6 mph

Other sizes close to 235/70R15

Questions

Can I replace 235/70R15 with 235/75R15?

235/75R15 is outside the ±3% rule as a replacement for 235/70R15: the diameter differs by +3.31%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 235/70R15 and 235/75R15?

235/75R15 is 0.93" taller and 0 mm wider; the sidewall is +0.46". At an indicated 60 mph you'd actually be doing 62.0 mph.

Will 235/75R15 fit on 235/70R15 wheels?

Both use a 15" rim, so the wheel diameter matches; check the wheel's width range for a 235 mm tire and the fender clearance.