Section Width105 mm (4.1")
Aspect Ratio398%
Rim Diameter40"
Overall Diameter1852 mm (72.9")
Sidewall Height418 mm
Circumference5818 mm
105/398R40 — Buy Tires

Everything to know about the 105/398R40 tire size

Size geometry

A 105/398R40 tire has a 105mm section width and a 398% aspect ratio, mounted on a 40-inch rim. Sidewall height works out to 417.9mm (16.45") and overall outside diameter is 1851.8mm (72.91"). At highway speed the tire completes about 172 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 105/398R40 is unavailable, the closest same-diameter substitutes on the same rim are 95/440R40 and 115/363R40. 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 105/398R40 you can upsize to 115/352R41 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 95/453R39 (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 105/398R40 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 105/398R40

tire_size.no_vehicles_found