Inner dual tires run hotter

[davidbrady]

Folks,

Anyone who's tested their tire temps with an IR thermometer knows that the inner tires on our drive axles run hotter. Some have attributed this to the the inners being closer to the power train and other mechanical systems, another possible explanation is that the inner duals don't get the cooling air that the outers do. I always thought that it was do to the road crown causing unequal tire loading. While all the above is true, Michelin confirms what others have published: the primary cause of inner tires running hotter is drive axle flex. The chassis weight bears down on the axle at two points inboard of the tires. This causes the axle, which is really a beam, to flex concave up which causes the inner tires to bear an incrementally greater amount of the load as compared to the outer tires. The articles below explain the phenomena well enough:

http://www.truckinginfo.com/article/stor...tires.aspx
http://www.truckinginfo.com/article/stor...tires.aspx