We're considering a new family hauler, tow vehicle for a travel trailer. I notice that the 2005 Landcruiser is rated to tow 6500, while the LX470 is only rated for 5000. The drivetrain is the same, so I assume that there is some kind of suspension issue. The earlier versions of the Lex are rated at 6500. Can anyone give me the cliff's notes on these?