255/80R17 vs 265/70R17

255/80R17 is 1.5" taller than 265/70R17 (4.4%)

Diameter difference−4.41%diameter 33.06" → 31.61"
255/80R17265/70R17
255/80R17265/70R17Difference
Overall diameter33.06"31.61"−1.46"
Section width10.04"10.43"+0.39"
Sidewall height8.03"7.30"−0.73"
Circumference103.9"99.3"−4.6"
Revolutions per mile610638+28
Wheel diameter17"17"±0"

Speedometer

ShowsActualDiff
30 mph28.7 mph−1.3
45 mph43.0 mph−2.0
60 mph57.4 mph−2.6
70 mph66.9 mph−3.1
80 mph76.5 mph−3.5

Gear ratio to match

CurrentEquivalent
3.423.27
3.553.39
3.733.57
4.103.92

265/70R17 is 1.46" shorter than 255/80R17, a −4.41% change in diameter. That is more than the 3% many tire shops use as a limit, so plan on recalibrating the speedometer and checking ABS and stability control.

Ground clearance changes by 0.73" (half the diameter change), and the tire needs 0.73" less room above it.

265/70R17 is 0.39" wider. On the same wheel offset about half of that, 0.20", moves toward the suspension and half toward the fender.

Both fit a 17" wheel; the sidewall is 0.73" shorter on 265/70R17.

Details: 255/80R17 in inches · 265/70R17 in inches · change sizes in the calculator

FAQ

What is the difference between 255/80R17 and 265/70R17?

265/70R17 is 1.46" shorter (−4.41%) and 0.39" wider than 255/80R17.

Will 265/70R17 change my speedometer?

Yes, by −4.41%. When the speedometer shows 60 mph you would be going 57.4 mph.

Can I replace 255/80R17 with 265/70R17?

It is a −4.4% diameter change, larger than the common 3% guideline, so check clearance and plan to recalibrate.