charlieaarons
Explorer
What about either 325/85R16 XMLs or 335/80R20 XZLs? Both pretty tall, very good load capacity (4600 and 5150 kg/axle respectively), designed to run at low pressures on sand.
Charlie
Charlie
Australian touring vehicle
- Thread starter The BN Guy
- Start date
Bluewater Australia
Observer
I just had a look at the specs for the NT (current model) OKA 4WD. It gets 19.5 x 8.25 wheels with 265/70R tyres; doesn't say what breed. Tour buses get a standard upgrade to 285/70R.
CTIS, beadlocks, 20" 'military spec' wheels/tyres, runflats, tubes and split rims are all optional accessories.
Out of curiosity I looked at Michelin XML - max speed 62mph (100km/h) and load range D; both too low. XZLs are a bit better at 68mph but they're all too tall except for the 11.00R16s (load range E).
CTIS, beadlocks, 20" 'military spec' wheels/tyres, runflats, tubes and split rims are all optional accessories.
Out of curiosity I looked at Michelin XML - max speed 62mph (100km/h) and load range D; both too low. XZLs are a bit better at 68mph but they're all too tall except for the 11.00R16s (load range E).
charlieaarons
Explorer
Isn't a load capacity of 4600kg/axle enough for a 5500kg vehicle? Who cares what the nominal "ply rating" is? All that tells you is the max inflation pressure. What really matters is the load index, which in the case of the 325 is 137 and the 335 is 141, but only 135 for the 11.00.
Charlie
whatcharterboat
Supporting Sponsor, Overland Certified OC0018
If I could throw my 50cents in here >>
The 325/85 R 16 XML are an excellent offroad tyre. Probably the best thing we've used but they aren't cheap. About $1200Aud each a few years back and Michelin really only like selling them to the military. 20,000 kays of mixed on/offroad use on a 6 ton truck and they are looking very ordinary. They start to get a harmonic wave wearing into the tread. Bit hard to explain. Never really seen it before with normal offroad tyres. There was a couple of sets at auction a few weeks back in Brisbane. Now sure what they brought.
Also for us they usually major mods to get them to fit under a little Jap truck like a FG or NPS. I guess that an OKA would be the same.
As for 20R's >>> Bluewater made the comment about the weight of the 19.5" wheels. While they are probably much heavier than they need to be for a 5 or 6 ton truck, the 20" rims available to wheel builder's here are way over the top. I know we are only talking half an inch but the weight difference is huge. Also the 20" tyres are also on the extra heavy side.
Getting back to the XML's >>> Being on a 16"rims is also a problem. Wheel builders only use tubeless 16"rims made for 4x4 cars. I know what the "load ratings" say but this goes out the window after a couple of years of hitting wash outs and corrugations. I'm not basing this on wheel specifications but wheel failures that I've actually seen. This is the problem when you are in the 5/6 ton bracket and want single rear wheels. Go for 16's and run the risk of wheel failure or go for 19.5's and put up with the weight but have peace of mind. All the guys we have built trucks for that are running XML's have changed or are in the process of changing to 19.5s.
If you can stay under or stay around that weight bracket you can get away with the 16"s safely so always keep the weight in mind and you'll escape the dramas.
whatcharterboat
Supporting Sponsor, Overland Certified OC0018
Yep. 16" XML's on the ASLAV's but the Bushmaster's have the XZL 20R's I think.
whatcharterboat
Supporting Sponsor, Overland Certified OC0018
It'd certainly be easy to load food, kids, gear, spare wheels and that odd dirtbike but wouldn't the windows blow out when you squashed everything down the back. Love that sunroof too.
BTW Would it come with that cool self loading roof rack/box system as well? I like it.
Bluewater Australia
Observer
Sure sounds like it would be, and there are evidently plenty of people here who know much more about this stuff than I do! So at the risk of taking this thread in yet another direction :bike_rider: I learnt a little tonight... having had in the back of my mind that I needed (and got) a load rating 'E' in the tyres I have, I saw that the 325/85R16 XMLs have a load rating 'D' in the USA... and figured that wasn't enough. But as I now know, the letters are a 'load range' rating more relevant to how much abuse a tyre will cop, not how much weight it can hold up (ply rating as charlieaarons points out). The 'load index' of the 325 XML says 5070lbs at 65psi; so plenty there. In fact 4600kg/axle.
But if they're really going to cost two or three times what I have, I'll be even happier with what I have!
Very educational stuff from others here too, thanks.
whatcharterboat
Supporting Sponsor, Overland Certified OC0018
Hey, I learnt something too. Charlie's must eat truck manuals for breakfast.
BTW Charlie when you come to Oz next year>>> as the Michelins are so expensive here, maybe you should throw in a couple of extra spares if you've got any lying around. You're welcome to leave them with us while you're on the road "just in case". Freight depot is just next door so it's no hassle. Only a thought. Plenty of time yet.
BTW Charlie when you come to Oz next year>>> as the Michelins are so expensive here, maybe you should throw in a couple of extra spares if you've got any lying around. You're welcome to leave them with us while you're on the road "just in case". Freight depot is just next door so it's no hassle. Only a thought. Plenty of time yet.
charlieaarons
Explorer
I am overwhelmed with your generous offer, thank you very much.
I carry the usual mounted spare plus another unmounted spare on the roof. I have 2 more virtually brand new tires. The truck has 29K miles (~47K km) and the tires (395/85R20 XZLs) are only about 25-30% worn. I figure if I can keep the truck in Aus. for 1-1/2 years I'd take about 4 trips, each lasting ~2-2.5 months. So I'd probably put about 7-10K miles (100-150 miles/day), times 4 = 28-40K miles. At the high end of that the tires would still be usable but only with ~6mm tread, so a change would be wise, keeping the best of the old ones for spares.
BTW I do have a lot of various specifications and manuals laying around and bookmarked in the computer, and also a really good memory. I have a complete wiring diagram for the U500, a full notebook of pages that open out, the CD workshop manual and a Star Diagnosis system on a PC. And lots of spare parts. Ranging from a shock, brake and hub parts and oil seals to a spare ECU, air compressor, fuel and water pumps, filters, etc.
Thanks again,
Charlie
I carry the usual mounted spare plus another unmounted spare on the roof. I have 2 more virtually brand new tires. The truck has 29K miles (~47K km) and the tires (395/85R20 XZLs) are only about 25-30% worn. I figure if I can keep the truck in Aus. for 1-1/2 years I'd take about 4 trips, each lasting ~2-2.5 months. So I'd probably put about 7-10K miles (100-150 miles/day), times 4 = 28-40K miles. At the high end of that the tires would still be usable but only with ~6mm tread, so a change would be wise, keeping the best of the old ones for spares.
BTW I do have a lot of various specifications and manuals laying around and bookmarked in the computer, and also a really good memory. I have a complete wiring diagram for the U500, a full notebook of pages that open out, the CD workshop manual and a Star Diagnosis system on a PC. And lots of spare parts. Ranging from a shock, brake and hub parts and oil seals to a spare ECU, air compressor, fuel and water pumps, filters, etc.
Thanks again,
Charlie
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engineer
Adventurer
I knew i had pics somewhere
There were like driving a limosine, very smooth. It was possibly due to the fact that they were origionally designed for around 3 ton, we had them pulling around 7-7.5t, don't tell anyone.......
