tyres on 80 series cruiser

thanks RL, that is interesting and helpful. Were you running the narrower cheesecutters on any of those vehicles? I think that would be one of the things that potentially helps on the economy front- and the higher pressures commonly associated with them, too.

one had bfg ats one desert duellers and the other mud terrains

It's interesting that you mention that. When reading an online resource at

http://www.michaelmcfadyenscuba.info/viewpage.php?page_id=574

a seemingly well experienced traveller and professional states:

The one thing that I do not do is let air out of the tyres when on rough roads. I do not understand this recent phenomenon that seems to have infected all four wheel drive clubs and magazines. I should point out that I have been driving four wheel drives professionally for work since 1977 in some of the most dramatic terrain in NSW, on roads normally closed to the public and through bush where there are not even roads.

During that time I have never let my tyres down (except of course on beaches). the primary reason for this was for most of the time I have never had the means to reinflate them again (eg work did not provide compressors for our vehicles and still does not). The only flat tyres I have ever suffered on dirt roads or off road were when driving old LandCruiser Utes with inner tube tyres through the bush (not on roads) and we were getting spiked by the burnt out remains of a certain bush. I have done a lot of trips with people since I purchased the Prado and we have never let our tyres down. The number of flat tyres could be counted on one hand.

Compare this to reports I read in magazines and club reports where up to 25% of the vehicles had flat tyres. The common thing was that they had deflated their tyres from normal pressures to 25 or so psi. I see no benefit at all in this except if you are stuck on a very rocky bit of track and you temporarily drop pressures to give yourself more grip to climb the hill.

I run 36 psi on the front and 40 psi on the back, all year round. There are no problems with this.

I don't know how he gets away with it but he's been to many places (including Simpson crossing), and the low pressure in the tyres and punctures coincides with your experience....

That reference sounds like an old fogey who's never done a desert trip.
I used split rims for 10 years and the best thing I ever did was move to tubeless. On the sharp stony desert roads, like we have in SA, lowering the pressures reduces the chance of punctures through the tread.

on the other hand phill ive seen first hand from running quality tubless tyres (mtr) and quality split rim tyres (dunlop) mated with quality tubes (michelin) through wooded areas (desert country is very fiendly on tyres)

and the tubelss tyres are lucky to last a day sometimes a matter of hours before being destroyed where as all you do if you do happen to get a flat with the splits is just remove the stake and patch the tube and keep going

going to tubeless tyres has cost me 000s

my last trip which was pretty tame destoyed a new style mtr which i treplaced with my one last brand new old style one which lasted only a few hours before being destroyed

"I don't know how he gets away with it"

rainbowprof

It could depend on what type of tyres he uses. Some manufacturers like Cooper for example recommend changing pressures for different road surfaces. I have used Wrangler TGs for years. They only come in four sizes: a 205R16, two 7.50x16s in different load ratings and a 14". Goodyear at head office (not at a dealer) will tell you to use factory pressures and don't let them down. In my case (a 205 on a Hilux) that is 25 front at all times and 25 to 34 rear depending on load. At those pressures how much lower would you want to go anyway?

I have had no problems with them everywhere from Sydney roads and freeways to mountain tracks and a lot of SA, Qld and NSW desert roads/tracks. All have been on those pressures without changing them except once when I drove to the top of Big Red. The car went up easily in third low with 14 front and 18 rear.

I use them on split rims only because I can remove the tyre as easy as can be if I ever have to. I don't like temporary plugs, particularly in the bush or Outback because the type of punctures you are likely to get in those areas are usually too big for them. I keep the openings in the wheels sealed with silicon and dismantle them before every major Outback trip. This ensures they are always easy to remove. I have never had a tube problem (Michelin) and find the tubes are always still slippery to touch when I dismantle them due to the chalk I put in on assembly.

Forgot to add, you will notice a small improvement in fuel consumption compared to heavy 265 or 285 LT tyres on the 8" wide GXL rims if you move to skinnies. But if you're currently running Grandtreks, then fuel consumption won't change much because the Grandtreks give good fuel consumption. The tyres on the split rims will wear quicker too, so there are swings and roundabouts.