CarSpecsHQ

245/70R17 vs 235/75R17

235/75R17 is a safe swap for 245/70R17 by the usual ±3% rule: the diameter differs by +1.23%.

17" rim
245/70R17 30.50" · 235/75R17 30.88" · drawn to scale

Side by side

245/70R17235/75R17Difference
Overall diameter30.50"30.88"+0.37" (+1.23%)
Section width245 mm235 mm-10 mm
Sidewall6.75"6.94"+0.19"
Rim17"17"same
Circumference95.8"97.0"+1.2"
Revs per mile661653-8
Ride height——+0.19"
Speedometer reads 60 mph60.060.7+0.7 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.7 mph

With 235/75R17 on a car calibrated for 245/70R17, the speedometer reads 59.3 mph when you're really doing 60, and the odometer under-counts by 1.2%.

Speedo showsActual speed
30 mph30.4 mph
45 mph45.6 mph
60 mph60.7 mph
70 mph70.9 mph
80 mph81.0 mph

Other sizes close to 245/70R17

Questions

Can I replace 245/70R17 with 235/75R17?

235/75R17 is a safe swap for 245/70R17 by the usual ±3% rule: the diameter differs by +1.23%.

What's the difference between 245/70R17 and 235/75R17?

235/75R17 is 0.37" taller and 10 mm narrower; the sidewall is +0.19". At an indicated 60 mph you'd actually be doing 60.7 mph.

Will 235/75R17 fit on 245/70R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 235 mm tire and the fender clearance.