CarSpecsHQ

245/75R17 vs 235/80R17

235/80R17 is a safe swap for 245/75R17 by the usual ±3% rule: the diameter differs by +1.06%.

17" rim
245/75R17 31.47" · 235/80R17 31.80" · drawn to scale

Side by side

245/75R17235/80R17Difference
Overall diameter31.47"31.80"+0.33" (+1.06%)
Section width245 mm235 mm-10 mm
Sidewall7.23"7.40"+0.17"
Rim17"17"same
Circumference98.9"99.9"+1.1"
Revs per mile641634-7
Ride height——+0.17"
Speedometer reads 60 mph60.060.6+0.6 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.6 mph

With 235/80R17 on a car calibrated for 245/75R17, the speedometer reads 59.4 mph when you're really doing 60, and the odometer under-counts by 1.1%.

Speedo showsActual speed
30 mph30.3 mph
45 mph45.5 mph
60 mph60.6 mph
70 mph70.7 mph
80 mph80.9 mph

Other sizes close to 245/75R17

Questions

Can I replace 245/75R17 with 235/80R17?

235/80R17 is a safe swap for 245/75R17 by the usual ±3% rule: the diameter differs by +1.06%.

What's the difference between 245/75R17 and 235/80R17?

235/80R17 is 0.33" taller and 10 mm narrower; the sidewall is +0.17". At an indicated 60 mph you'd actually be doing 60.6 mph.

Will 235/80R17 fit on 245/75R17 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.