255/35R18 vs 265/35R18Tire Size Comparison

Safe

The 1.1% diameter difference is within the accepted 3% tolerance.

255/35R18636mm dia265/35R18643mm dia+3.5mm

Comparison Details

Overall Diameter635.7 vs 642.7 mm (+7.0 mm)
Diameter Difference+1.10%
Section Width255 vs 265 mm (+10 mm)
Sidewall Height89.3 vs 92.8 mm (+3.5 mm)
Circumference1997.1 vs 2019.1 mm
Clearance Change+3.5 mm
Speedometer Error+1.10%
Revs/Mile806 vs 797

Speedometer Correction

When switching from 255/35R18 to 265/35R18, your speedometer will differ from actual speed.

SpeedometerActual SpeedDifference
30 km/h30.3 km/h+0.3 km/h
40 km/h40.4 km/h+0.4 km/h
50 km/h50.6 km/h+0.6 km/h
60 km/h60.7 km/h+0.7 km/h
70 km/h70.8 km/h+0.8 km/h
80 km/h80.9 km/h+0.9 km/h
90 km/h91.0 km/h+1.0 km/h
100 km/h101.1 km/h+1.1 km/h
110 km/h111.2 km/h+1.2 km/h
120 km/h121.3 km/h+1.3 km/h
130 km/h131.4 km/h+1.4 km/h

Individual Tire Size Details

255/35R18
Full specifications, compatible vehicles, and alternatives
265/35R18
Full specifications, compatible vehicles, and alternatives

Practical Guidance

Switching from 255/35R18 to 265/35R18 is within the industry-accepted 3% diameter tolerance. Your speedometer, ABS, and traction control should function normally. Both sizes fit the same 18-inch rim, so no wheel change is needed.

The 3% diameter tolerance is a widely accepted industry guideline referenced by the ETRTO and most vehicle manufacturers. When in doubt, consult your vehicle's owner's manual or a qualified tire professional. For U.S. tire safety standards and recalls, see the NHTSA Tire Safety page.

Frequently Asked Questions

Safe. The overall diameter differs by 1.10%, width changes by 10mm.

Speedometer error will be 1.10%. At an indicated 100 km/h, actual speed is about 101.1 km/h.

Ground clearance changes by +3.5mm per side.