CarSpecsHQ

225/75R17 vs 255/70R17

255/70R17 is a safe swap for 225/75R17 by the usual ±3% rule: the diameter differs by +2.53%.

17" rim
225/75R17 30.29" · 255/70R17 31.06" · drawn to scale

Side by side

225/75R17255/70R17Difference
Overall diameter30.29"31.06"+0.77" (+2.53%)
Section width225 mm255 mm+30 mm
Sidewall6.64"7.03"+0.38"
Rim17"17"same
Circumference95.2"97.6"+2.4"
Revs per mile666649-16
Ride height——+0.38"
Speedometer reads 60 mph60.061.5+1.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.5 mph

With 255/70R17 on a car calibrated for 225/75R17, the speedometer reads 58.5 mph when you're really doing 60, and the odometer under-counts by 2.5%.

Speedo showsActual speed
30 mph30.8 mph
45 mph46.1 mph
60 mph61.5 mph
70 mph71.8 mph
80 mph82.0 mph

Other sizes close to 225/75R17

Questions

Can I replace 225/75R17 with 255/70R17?

255/70R17 is a safe swap for 225/75R17 by the usual ±3% rule: the diameter differs by +2.53%.

What's the difference between 225/75R17 and 255/70R17?

255/70R17 is 0.77" taller and 30 mm wider; the sidewall is +0.38". At an indicated 60 mph you'd actually be doing 61.5 mph.

Will 255/70R17 fit on 225/75R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 255 mm tire and the fender clearance.