CarSpecsHQ

225/75R17 vs 245/70R17

245/70R17 is a safe swap for 225/75R17 by the usual ±3% rule: the diameter differs by +0.71%.

17" rim
225/75R17 30.29" · 245/70R17 30.50" · drawn to scale

Side by side

225/75R17245/70R17Difference
Overall diameter30.29"30.50"+0.22" (+0.71%)
Section width225 mm245 mm+20 mm
Sidewall6.64"6.75"+0.11"
Rim17"17"same
Circumference95.2"95.8"+0.7"
Revs per mile666661-5
Ride height——+0.11"
Speedometer reads 60 mph60.060.4+0.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.4 mph

With 245/70R17 on a car calibrated for 225/75R17, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.7%.

Speedo showsActual speed
30 mph30.2 mph
45 mph45.3 mph
60 mph60.4 mph
70 mph70.5 mph
80 mph80.6 mph

Other sizes close to 225/75R17

Questions

Can I replace 225/75R17 with 245/70R17?

245/70R17 is a safe swap for 225/75R17 by the usual ±3% rule: the diameter differs by +0.71%.

What's the difference between 225/75R17 and 245/70R17?

245/70R17 is 0.22" taller and 20 mm wider; the sidewall is +0.11". At an indicated 60 mph you'd actually be doing 60.4 mph.

Will 245/70R17 fit on 225/75R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 245 mm tire and the fender clearance.