255/35R18 vs 265/35R18

265/35R18 is 0.3" taller than 255/35R18 (1.1%)

Diameter difference+1.10%diameter 25.03" → 25.30"
255/35R18265/35R18
255/35R18265/35R18Difference
Overall diameter25.03"25.30"+0.28"
Section width10.04"10.43"+0.39"
Sidewall height3.51"3.65"+0.14"
Circumference78.6"79.5"+0.9"
Revolutions per mile806797−9
Wheel diameter18"18"±0"

Speedometer

ShowsActualDiff
30 mph30.3 mph+0.3
45 mph45.5 mph+0.5
60 mph60.7 mph+0.7
70 mph70.8 mph+0.8
80 mph80.9 mph+0.9

Gear ratio to match

CurrentEquivalent
3.423.46
3.553.59
3.733.77
4.104.15

265/35R18 is 0.28" taller than 255/35R18, a +1.10% change in diameter, inside the 3% range most shops treat as a safe swap.

Ground clearance changes by 0.14" (half the diameter change), and the tire needs 0.14" more room above it.

265/35R18 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 18" wheel; the sidewall is 0.14" taller on 265/35R18.

Details: 255/35R18 in inches · 265/35R18 in inches · change sizes in the calculator

FAQ

What is the difference between 255/35R18 and 265/35R18?

265/35R18 is 0.28" taller (+1.10%) and 0.39" wider than 255/35R18.

Will 265/35R18 change my speedometer?

Yes, by +1.10%. When the speedometer shows 60 mph you would be going 60.7 mph.

Can I replace 255/35R18 with 265/35R18?

Often yes: the diameter change of +1.1% is within the common 3% guideline. Check the load index, speed rating and clearance.