The photo shows an extra layer of rubber around the base of the tread blocks where they meet the tire casing. This extra layer is supposed to reduce the chance that a stone will become lodged in the tread, possibly leading to a puncture.
Chip. I think the term Toyo use is "stone ejectors".
The largest 285/70R19.5 I have found in the states has a 35.4" OD. I have not seen a 285/75 here?
Leon, Ours are only a 285/70R but they are 899mm O.D.??????? (Late edit: Doh. 899mm is 35.4" so that is the same, did you think they were bigger?)
Check here.
http://www.toyo.com.au/LTRPDFs/M608z.pdf Somewhere I posted a pic of them standing next to an XZL which are about 930mm. They look very close when you stand them next to one another.
Here it is. See? The O.D. difference isn't as noticeable as you might think.
For usa availability those Michelin XDE2+ look like the choice tire right now (IMO). Only because they are specified to be about 1" larger in diameter than the M608z we can get here.
XDE2+ are available here in a 305 x 19.5" which are IIRC about 930mm. The only trouble with them is they are made as a high milage/ highway / drive tyre with a very hard compound. They chip easily and the tread blocks tend to rip right off in rocky country. For the purpose of which they were designed for though, they are excellent. Standard fitment on the bigger Isuzu road trucks.
Bridgestone here also do a big 305 drive tyre that does stand up very well offroad but the pattern would hardly suit mud or anything at all slippery. They were on that truck I did a thread on . "Bight to Cape York". After all the abuse they gave them over the 18 month period, they were still in great shape.
The other 19.5" choice we have is the Continental HCT1 "construction" tyre at 305 . About 930mm too I think. The Toyo is still the only Mud ' n ' Snow pattern though and they're extra tough too. Next best pattern is the Hankook AM02 but they are a fair bit smaller and at half life they turn back into a standard zig-zag drive tyre pattern with nowhere for the mud to escape out the sides. Hard to explain. They look good when new anyway before the half knobs wear down.
We all should have ordered ATW campers from the usa when the AU exchange rate was 68% of the us dollar.
Or when it was 55% 18months ago. It's up around 90% now. I know a guy here who restores Mopar muscle cars and exports them back to you guys when your dollar peaks. Who would have thought?
BTW Found a pic of that particular bus on Toyo's. When it was new. The other 649 runs exactly the same body but I'll try and get a pic of it too. Just to complete the post.
Building a beautiful one of these ATM for a tour company in Central Oz. . Really optioned up. Should be done by the end of next week.
Leon, how much are the Toyo M608Z's in the US?