Michelin Load & Inflation Tables

[davidbrady]

This info came from the Michelin Truck Tire Data Book April 2013. They spec a minimum dual spacing of 13.8" for the Michelin XZA2-Energy, 315/80R22.5, on 9" wheels (page 37). On 8.25" wheels they spec a minimum dual spacing is 13.5" (page 97).

They also go on to say:

DUAL SPACING
It is also important that sufficient space is provided between dual tires to allow air to flow and cool the tires and to prevent the tires from rubbing against one another.

To make sure dual spacing is correct, simply measure from the outside edge of the outer tire to the outside edge of the inner tire of the dual assembly. This will give you the center to center distance of the duals across that axle. Refer to the minimum dual spacing column in the application data books.

If you're contemplating a switch to 315's on 8.25" wheels it's probably a good idea to measure your current "dual spacing". (You can use any reference point on the tread that you like, but you have to measure at the same place on both tires. If you're running 8.25" wheels and the spacing is greater than or equal to 13.5" then you can run 315's on your 8.25" wheels.

For a point of reference, I measured the dual wheel spacing on my LXi. I'm running XZA2 Energy's 315/80/22.5's LRL on 9" wheels, Alcoa part number 893603 (hub pilot).

Dual Wheel Spacing: 13.88"
Space Between Tires (Loaded): 0.65"

I put a copy of the Michelin Truck Tire Data Book April 2013 in our Document Library at Document Library > Chassis > Tires and Wheels.