3 Discoveries, 3 different tyre brands and 17,000 outback km's. Who won? (long post)

What tyre pressures were run on each vehicle and did you change this or experiment for different road conditions?

Also, nobody using a Stone Stomper or similar to protect rear windows?

Cheers,
Scott

PS ... excellent report. I can think of lots of questions other than tyre related too. You could do a write-up in the Trip Report section.

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Originally Posted by LRD414

What tyre pressures were run on each vehicle and did you change this or experiment for different road conditions?

Also, nobody using a Stone Stomper or similar to protect rear windows?

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Regarding tyre pressures: I didn't methodically test various tyre pressures, I just used seat-of-the-pants and experience from previous trips to decide on pressures.

These were my COLD pressures most of the time: 255/55 r19
REAR
Highway: 42 PSI
Dirt: 30-32 PSI
FRONT
Highway: 38 PSI
Dirt: 28-30 PSI

My understanding is the other Disco's ran very similar pressures. The Landcruiser's ran 33 inch tyres and aired down to lower pressures than what the Disco's did.

Regarding stone guards: the 80 series used a stone stomper and I must admit it was brilliant. Nothing better for those types of roads in my opinion.

the problem with going fast over corrugations is that you reduce steering and braking. i'm not really sure how to explain why.

Great report thanks.
Those BFG ATs look like mine did on the rear of my D2a after I completed the Gibb River Road and Mitchell Falls in 2014. Heaps of chipping but otherwise excellent tyre.

Cheers,

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Originally Posted by Eevo

the problem with going fast over corrugations is that you reduce steering and braking. i'm not really sure how to explain why.

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I totally agree. A 4wd + camper takes a lot of stopping anytime on dirt, but it is significantly more on corrugations. I believe it is because ABS systems are actually calibrated well for dirt. Generally the wheels slide slighty which builds up gravel/sand in front of the tyres which adds braking performance on dirt. On corrugations the wheels never really get that constant contact.

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Originally Posted by pawky

The collapsed strut was on the 80 series.

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:D No problem then. Was heading up the Kimberly way soon and was wondering.

I had a pedders shock fall in half on the Mitchell plateau rd. it was on a 110.

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Originally Posted by cjc_td5

Great report thanks.
Those BFG ATs look like mine did on the rear of my D2a after I completed the Gibb River Road and Mitchell Falls in 2014. Heaps of chipping but otherwise excellent tyre.

Cheers,

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That is an excellent report:)

My BFG's on the D4 are way worse than your pic,i should actually post up a pic,but don't want to hijack the thread.

They had already done 20k,the damage i put down to a lot of k's at high speed on very rocky roads,combined with pressures that were probably a bit higher than they should have been.

I also find them an excellent tyre,apart from this issue,which is well documented.

Fantastic report pawky:) we are setting our vehicle up at the moment to tow a caravan around the country. you have really inspired me.
we have 19" rims on the D4 and have been procrastinating about tyre choice. also the vehicle with the stone stomper did they have issues with bull dust building up on top? and how did it perform in wet muddy conditions?
thanks again cannot wait to hit the tracks with a permagrin LOL

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Originally Posted by BSM

"You never really get fast enough to smooth out the bumps."

I've had conflicting theories about this approach to driving coruugations. On the one hand, there can definitely be a particular speed at which the ride smooths out. I assume it's a point where the frequency of the corrugations matches some sort of harmonic frequency of the springs and dampers of the suspension resulting in the cabin getting a nice smooth ride.

What I've been wondering though is if at that same speed, the dampers are getting a total hammering and thus are prone to overheating and blowing a relief valve..

If that is true then then the alternative theory of driving slower, and putting up with the discomfort in the cabin is actually better on the car overall.

What do you think?

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I have the same issue steering my grader getting rid of the corrugations.Speed is the story,lowering tyre pressures on a vehicle and roadspeed could well be the answer;););).
Andrew