Section Width515 mm (20.3")
Aspect Ratio39%
Rim Diameter18"
Overall Diameter859 mm (33.8")
Sidewall Height201 mm
Circumference2698 mm
515/39R18 — Buy Tires

Everything to know about the 515/39R18 tire size

Size geometry

A 515/39R18 tire has a 515mm section width and a 39% aspect ratio, mounted on a 18-inch rim. Sidewall height works out to 200.8mm (7.91") and overall outside diameter is 858.9mm (33.81"). At highway speed the tire completes about 371 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 515/39R18 is unavailable, the closest same-diameter substitutes on the same rim are 505/40R18 and 525/38R18. 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 515/39R18 you can upsize to 525/36R19 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 505/42R17 (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 515/39R18 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 515/39R18

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