Hi Michael. Welcome.
Initially I wanted 19.5 inch rims but I heard that when you let the air out of them the tyres don't necessarily balloon out.
This is my opinion and I've said it before but for an allround, allterrain, most economical setup (particularly the Hankooks over the dearer Bridgestone), the 19.5 " are hard to go past, however for pure offroad, the XZL's are probably the pick (unless money is no object or you can look at the XML's).
More important than how much they "balloon out", is how long a footprint they can give. If you read the "FG fleet mechanic interview" the guys that run these every day on the beach still run around 60PSI unless it's extra soft and they might go down to 40. They also run the XZL "road" version when they can get them too which are the same size but with a conventional tread and therefore give extra milage.
I then noticed that Earthcruiser had done some serious sand (Madigan line etc) with the 16inch Michelin XZL combination so I figured it was a good direction to go in.
This truck was setup with all our standard long travel suspension, dual shocks, XZL tyre combo etc that has been around for 10 years or more on tour buses and older motorhomes. So yeah definitely a well proven setup and a good direction to go in. The 19.5"s are relatively new to Canters as a SRW conversion.
If my interpretation is correct, to run Michelin XZLs I can only use a 16 X 6 or 16 X 6.5 inch rim. And for Coopers I need at least 16 X 7 inches and their load rating is lower.
No. Not quite right. The standard 6.00 rims are OK but 7.00 are closer to the correct width for an XZL 100R/16 tyre. If you are going to get the wider 7.00 rims, then you can also get them made with the correct offset. The OEM wheels don't give the correct wheel alignment (front to back) but as I said you can get away with it.
However the final problem is getting an engineer to agree to the idea, in Canberra they will only accept a NSW or ACT certified engineer. (You mention Qld to ACT rego officials and they shudder)
Given the 4 inch increase in Diameter is a radical change from standard has anyone managed to get an Engineer to agree to the XZLs described on an FG in NSW/ACT?
We build a lot of commercial vehicles for NSW including some for Government agencies and many run the XZL's. Legally. Not sure about ACT. I know NSW are a bit over the top on some issues such as exhausts. All the NSW vehicles have had to have a rear / roof top exhaust outlet . See the that little white SWB for example. Adding that much length is just ridiculous for a little turbo truck.
My final point of confusion is that the XZL is classed as an "off road" tyre, can it still be used legally "on road" in Australia?
Michael, I know it’s a big claim but to quote Michelin on the XZL, they are “designed for exceptional traction and handling on all terrains including snow, sand, mud or highway”. See the "highway" bit, so they are a very different classification to an Agricultural tyre.
I took this pick today of an almost completed bus on XZL's with the OEM rims. It''ll probably spend most of it's life in sand.