CarSpecsHQ

245/75R17 vs 275/70R17

275/70R17 is a safe swap for 245/75R17 by the usual ±3% rule: the diameter differs by +2.19%.

17" rim
245/75R17 31.47" · 275/70R17 32.16" · drawn to scale

Side by side

245/75R17275/70R17Difference
Overall diameter31.47"32.16"+0.69" (+2.19%)
Section width245 mm275 mm+30 mm
Sidewall7.23"7.58"+0.34"
Rim17"17"same
Circumference98.9"101.0"+2.2"
Revs per mile641627-14
Ride height——+0.34"
Speedometer reads 60 mph60.061.3+1.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.3 mph

With 275/70R17 on a car calibrated for 245/75R17, the speedometer reads 58.7 mph when you're really doing 60, and the odometer under-counts by 2.2%.

Speedo showsActual speed
30 mph30.7 mph
45 mph46.0 mph
60 mph61.3 mph
70 mph71.5 mph
80 mph81.8 mph

Other sizes close to 245/75R17

Questions

Can I replace 245/75R17 with 275/70R17?

275/70R17 is a safe swap for 245/75R17 by the usual ±3% rule: the diameter differs by +2.19%.

What's the difference between 245/75R17 and 275/70R17?

275/70R17 is 0.69" taller and 30 mm wider; the sidewall is +0.34". At an indicated 60 mph you'd actually be doing 61.3 mph.

Will 275/70R17 fit on 245/75R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.