CarSpecsHQ

235/80R17 vs 275/70R17

275/70R17 is a safe swap for 235/80R17 by the usual ±3% rule: the diameter differs by +1.11%.

17" rim
235/80R17 31.80" · 275/70R17 32.16" · drawn to scale

Side by side

235/80R17275/70R17Difference
Overall diameter31.80"32.16"+0.35" (+1.11%)
Section width235 mm275 mm+40 mm
Sidewall7.40"7.58"+0.18"
Rim17"17"same
Circumference99.9"101.0"+1.1"
Revs per mile634627-7
Ride height——+0.18"
Speedometer reads 60 mph60.060.7+0.7 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.7 mph

With 275/70R17 on a car calibrated for 235/80R17, the speedometer reads 59.3 mph when you're really doing 60, and the odometer under-counts by 1.1%.

Speedo showsActual speed
30 mph30.3 mph
45 mph45.5 mph
60 mph60.7 mph
70 mph70.8 mph
80 mph80.9 mph

Other sizes close to 235/80R17

Questions

Can I replace 235/80R17 with 275/70R17?

275/70R17 is a safe swap for 235/80R17 by the usual ±3% rule: the diameter differs by +1.11%.

What's the difference between 235/80R17 and 275/70R17?

275/70R17 is 0.35" taller and 40 mm wider; the sidewall is +0.18". At an indicated 60 mph you'd actually be doing 60.7 mph.

Will 275/70R17 fit on 235/80R17 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.