That's very interesting clarky, I take my bigger tyres off when towing the van and go back to my standard second set.
A few years ago (200
when I was in Kalgoolie I met a fellow at the caravan park there with a WH CRD with oversize tyres, he was towing a 3t +Bushtracker. Believe it or not he had a busted/twisted tail shaft and the rear uni had let go. The vehicle was still under warranty and JA refused to fix it under warranty because the vehicle had oversize tyres.
He was arguing that the drive shaft was weak and had been sitting there for over a month and not getting anywhere...I don't know how he got on with it.
After seeing that I'm a bit dubious about towing heavy trailers with oversize tyres
The local tyre dealer mentioned to me when I got the oversize tyres that he wouldn't recommend that I tow my van with them on,besides I really only bought them for offroading and beach fishing at Fraser