Seems to be some slight confusion in terms.
Dual is when two tires are mounted on the same end of one axle. This gives a total of four tires on the one axle.
Tandem is when there are two axles spaced close together.
Most Class-C and Class-A RV have single axle, dual rear tires
A few very large Class-A have dual rear tires on a single axle plus a single axle "tag" to add load capacity. This would be a "tandem axle" setup with one axle being single and one dual.
The load reduction for "dual" application is seen in both LT and Heavy truck "TBR" size tire Load Inflation charts. Passenger tires do not have a "dual" load as they are not intended, designed or tested to be applied in dual application. ST tires in the Tire & Rim Association yearbook do show both single and dual loads.
I do not remember ever seeing an RV with Dual Tandem axles while most over the highway heavy truck trailers are dual tandem setup.
I have seen some construction flat bed trailers with dual tandem setup but do not know if they were ST or truck tires.
I do wish I could find the Goodyear publication which suggested a load reduction for tandem application of tires. The references so far simply pointed to other web pages that claimed there were GY documents but didn't point to the actual documents.
I for one would support such a load reduction. There is good science that would support that this reduction become part of the regulations and design standards. While RV manufacturers would of course object I doubt there would be any tire companies that would try and oppose such a change if the change were supported through mathamatical modeling.
I am trying to get access to the Finite Eliment software but I cannot afford to buy a copy $$$$ and cannot expect this program to be run by a major company that doesn't currently market ST tires unless I can sell the idea to them. Finding that Goodyear publication would make my job easier.
