CarSpecsHQ

245/65R17 vs 235/70R17

235/70R17 is a safe swap for 245/65R17 by the usual ±3% rule: the diameter differs by +1.40%.

17" rim
245/65R17 29.54" · 235/70R17 29.95" · drawn to scale

Side by side

245/65R17235/70R17Difference
Overall diameter29.54"29.95"+0.41" (+1.40%)
Section width245 mm235 mm-10 mm
Sidewall6.27"6.48"+0.21"
Rim17"17"same
Circumference92.8"94.1"+1.3"
Revs per mile683673-9
Ride height——+0.21"
Speedometer reads 60 mph60.060.8+0.8 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.8 mph

With 235/70R17 on a car calibrated for 245/65R17, the speedometer reads 59.2 mph when you're really doing 60, and the odometer under-counts by 1.4%.

Speedo showsActual speed
30 mph30.4 mph
45 mph45.6 mph
60 mph60.8 mph
70 mph71.0 mph
80 mph81.1 mph

Other sizes close to 245/65R17

Questions

Can I replace 245/65R17 with 235/70R17?

235/70R17 is a safe swap for 245/65R17 by the usual ±3% rule: the diameter differs by +1.40%.

What's the difference between 245/65R17 and 235/70R17?

235/70R17 is 0.41" taller and 10 mm narrower; the sidewall is +0.21". At an indicated 60 mph you'd actually be doing 60.8 mph.

Will 235/70R17 fit on 245/65R17 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.