Section Width265 mm (10.4")
Aspect Ratio78%
Rim Diameter18"
Overall Diameter871 mm (34.3")
Sidewall Height207 mm
Circumference2735 mm
265/78R18 — Buy Tires

Everything to know about the 265/78R18 tire size

Size geometry

A 265/78R18 tire has a 265mm section width and a 78% aspect ratio, mounted on a 18-inch rim. Sidewall height works out to 206.7mm (8.14") and overall outside diameter is 870.6mm (34.28"). At highway speed the tire completes about 366 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 265/78R18 is unavailable, the closest same-diameter substitutes on the same rim are 255/81R18 and 275/75R18. Both keep your speedometer reading within 1% — safe for daily use, ABS, and stability control. Always verify load and speed ratings before swapping.

Plus / minus sizing options

For a 265/78R18 you can upsize to 275/71R19 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 255/86R17 (minus-one) for a softer ride or winter setup. Both stay inside the Âą3% diameter tolerance that ABS and TPMS systems expect.

Vehicle compatibility

0 vehicles in our database run the 265/78R18 tire size from the factory. Aftermarket fitment depends on rim width, offset, and clearance — match these specs to your wheel before purchasing tires.

Vehicles Using 265/78R18

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