I took my 31"s to UPS, they put it on the scale and wanted like $27 a tire.
Then I took it to FedEX and they wanted I think it was like $11. They said they had a special rate for tires. No boxed, just stick the label to it and rap it in tape to cover the label... I called DHL but they were higher than FedEx quote, and they did not have a store near me to get a quote.