255/75R17 vs 265/70R17

255/75R17 is 0.5" taller than 265/70R17 (1.4%)

Diameter difference−1.41%diameter 32.06" → 31.61"
255/75R17265/70R17
255/75R17265/70R17Difference
Overall diameter32.06"31.61"−0.45"
Section width10.04"10.43"+0.39"
Sidewall height7.53"7.30"−0.23"
Circumference100.7"99.3"−1.4"
Revolutions per mile629638+9
Wheel diameter17"17"±0"

Speedometer

ShowsActualDiff
30 mph29.6 mph−0.4
45 mph44.4 mph−0.6
60 mph59.2 mph−0.8
70 mph69.0 mph−1.0
80 mph78.9 mph−1.1

Gear ratio to match

CurrentEquivalent
3.423.37
3.553.50
3.733.68
4.104.04

265/70R17 is 0.45" shorter than 255/75R17, a −1.41% change in diameter, inside the 3% range most shops treat as a safe swap.

Ground clearance changes by 0.23" (half the diameter change), and the tire needs 0.23" 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 0.23" shorter on 265/70R17.

Details: 255/75R17 in inches · 265/70R17 in inches · change sizes in the calculator

FAQ

What is the difference between 255/75R17 and 265/70R17?

265/70R17 is 0.45" shorter (−1.41%) and 0.39" wider than 255/75R17.

Will 265/70R17 change my speedometer?

Yes, by −1.41%. When the speedometer shows 60 mph you would be going 59.2 mph.

Can I replace 255/75R17 with 265/70R17?

Often yes: the diameter change of −1.4% is within the common 3% guideline. Check the load index, speed rating and clearance.