CarSpecsHQ

255/75R17 vs 275/70R17

275/70R17 is a safe swap for 255/75R17 by the usual ±3% rule: the diameter differs by +0.31%.

17" rim
255/75R17 32.06" · 275/70R17 32.16" · drawn to scale

Side by side

255/75R17275/70R17Difference
Overall diameter32.06"32.16"+0.10" (+0.31%)
Section width255 mm275 mm+20 mm
Sidewall7.53"7.58"+0.05"
Rim17"17"same
Circumference100.7"101.0"+0.3"
Revs per mile629627-2
Ride height——+0.05"
Speedometer reads 60 mph60.060.2+0.2 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.2 mph

With 275/70R17 on a car calibrated for 255/75R17, the speedometer reads 59.8 mph when you're really doing 60, and the odometer under-counts by 0.3%.

Speedo showsActual speed
30 mph30.1 mph
45 mph45.1 mph
60 mph60.2 mph
70 mph70.2 mph
80 mph80.2 mph

Other sizes close to 255/75R17

Questions

Can I replace 255/75R17 with 275/70R17?

275/70R17 is a safe swap for 255/75R17 by the usual ±3% rule: the diameter differs by +0.31%.

What's the difference between 255/75R17 and 275/70R17?

275/70R17 is 0.10" taller and 20 mm wider; the sidewall is +0.05". At an indicated 60 mph you'd actually be doing 60.2 mph.

Will 275/70R17 fit on 255/75R17 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.