CarSpecsHQ

235/80R17 vs 295/70R17

295/70R17 is outside the ±3% rule as a replacement for 235/80R17: the diameter differs by +4.58%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

17" rim
235/80R17 31.80" · 295/70R17 33.26" · drawn to scale

Side by side

235/80R17295/70R17Difference
Overall diameter31.80"33.26"+1.46" (+4.58%)
Section width235 mm295 mm+60 mm
Sidewall7.40"8.13"+0.73"
Rim17"17"same
Circumference99.9"104.5"+4.6"
Revs per mile634606-28
Ride height——+0.73"
Speedometer reads 60 mph60.062.7+2.7 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.7 mph

With 295/70R17 on a car calibrated for 235/80R17, the speedometer reads 57.4 mph when you're really doing 60, and the odometer under-counts by 4.6%.

Speedo showsActual speed
30 mph31.4 mph
45 mph47.1 mph
60 mph62.7 mph
70 mph73.2 mph
80 mph83.7 mph

Other sizes close to 235/80R17

Questions

Can I replace 235/80R17 with 295/70R17?

295/70R17 is outside the ±3% rule as a replacement for 235/80R17: the diameter differs by +4.58%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 235/80R17 and 295/70R17?

295/70R17 is 1.46" taller and 60 mm wider; the sidewall is +0.73". At an indicated 60 mph you'd actually be doing 62.7 mph.

Will 295/70R17 fit on 235/80R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 295 mm tire and the fender clearance.