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

[pawky]

Last year I had the awesome opportunity to travel some of Australia's great outback roads with some family and friends. The convoy included 3 different Land Rovers on 3 different tyre brands and I've been meaning to write this post ever since we got back in October 2014 (yeah, yeah, I know, procrastination is one of my talents). In particular I thought people might be interested in how the tyres fared on some of Australia's toughest roads, especially when each vehicle was setup very similarly.

What vehicles and tyres did we take?
Overall we had 5 vehicles set up very similarly which makes for an interesting comparison. All vehicles had new tyres fitted within 6 weeks of the beginning of the trip.

1. Discovery 3 TDV6 2.7L
Towing: camper trailer (1300 kg approx.)
Passengers: 4 adults + child
Cargo: twin drawers + twin fridges installed
Tyres: 265/65 r17 BFGoodrich All Terrain

2. Discovery 4 SDV6 3.0L
Towing: camper trailer (1300 kg approx.)
Passengers: 2 adults + 2 kids
Cargo: twin drawers + twin fridges installed
Tyres: 255/55 r19 Cooper Zeon LTZ

3. Discovery 4 SDV6 3.0L
Towing: camper trailer (1300 kg approx.)
Passengers: 2 adults + 3 kids
Cargo: twin drawers + twin fridges installed
Tyres: 255/55 r19 Goodyear Wrangler MTR

4. Landcruiser 200 Series
Towing: camper trailer (1300 kg approx.)
Passengers: 2 adults + 3 kids
Cargo: twin drawers + twin fridges installed
Tyres: BFGoodrich All Terrain 33"

5. Landcruiser 80 Series
Towing: camper trailer (1000 kg approx.)
Passengers: 2 adults + 3 kids
Cargo: twin drawers + twin fridges installed
Tyres: BFG KM2 Mud Terrain 33"

Where did we go?

http://www.aulro.com/afvb/members/pawky-albums-general+photos-picture5413-outback-trip-2014.png

Overall we travelled approx. 17,000 kms. In summary the trip included:
Newcastle to Alice Springs
Alice Springs to Purnululu (Bungle Bungle) via the Tanami Track (and Wolfe Creek Crater)
Purnululu to Kunnunurra
Kunnunurra to Broome via the Gibb River Road and Mitchell Plateau
Broome to Pilbara
Pilbara to Ningaloo
Ningaloo to Geraldton
Geraldton to Leonora
Leonora to Uluru via the Great Central Road
Uluru to Newcastle

What were the road conditions like?
Generally they were better than we expected (or maybe feared).
Tanami Track: Most of it was well graded and wide. There were lots of mining trucks on the road and I suspect the road was in good nick due to mine maintenance. The edges were often very soft so whenever possible we drove straight down the middle of the road. It was corrugated but 80-90kph seemed the right speed to reduce the vibrations.
Bungle Bungle Roads: This was in surprisingly good condition. I have been there before when the roads were much worse.
Gibb River Road: Not too bad. Blacktop extends all the way to El Questro now (on the east end) so you get almost all the way to the Pentecost River before you hit the dirt. The road was corrugated but most of the time it was possible to travel reasonably fast (80km hr approx) and smooth out the bumps.
Kalumburu and Mitchell Plateau Road: These roads were the hardest of all in my opinion. Some parts of the Kalumburu Rd were freshly graded and some desperately needed grading. The corrugations in some areas were huge. The Mitchell Plateau Road is a difficult road because it is winding and narrow and rough. You never really get fast enough to smooth out the bumps.
Pilbara Roads: They were generally well maintained. Corrugated but not severely.
Great Central Road: This road was almost as difficult as the Kalumburu Road. It did not have as many corrugations as other roads but was is definitely the rockiest. In fact, in our last 200kms of dirt for the entire trip (almost at Uluru) we smashed two rear windows in 20 mins.

What tyre damage did we get?
Overall we received very few punctures on the rough roads.

BFG All Terrain: 1 tyre staked (Landcruiser) near Bells Gorge. To be fair this puncture was due to driving too fast on a narrow track near Bells Gorge to find the Ranger and organise a rescue helicopter for another tourist who had a severe fall and compound femur fracture (It's another story for another day, but if you can afford it satellite phones are essential).
Goodyear MTR: 1 tyre slashed by a razor blade looking stone when driving into 80 mile beach. We were going slow and the road was super smooth ? just got unlucky. The tyre was repaired and kept as an emergency-only spare.
BFG Mud Terrain: 1 tyre destroyed when a shock absorber strut collapsed and went through the inside wall of the tyre.
Cooper LTZ: 2 punctures but both were nails and screws when in major towns/cities.

So which tyres survived the best?
I tried to take photos of the tyres on each Discovery after we finished the dirt but before we started the highway driving again. It is VERY hard to tell from photos but here are my thoughts:

The Cooper Zeon LTZs survived the roads the best. They clearly had the fewest cuts, chips and general damage.
The Goodyear MTRs were the next best. They had some chipping around the edge of the tread blocks (as expected) and possibly wore the most of all tyres but they did well.
The BFG Mud Terrains looked similar to the MTRs.
The BFG All Terrains clearly suffered the most chipping and general damage. Even my father-in-law, who is a BFG All Terrain die-hard, was shocked how they looked compared to the other tyres. They were not in poor condition, but they were visibly worse than the others.

Interestingly, the BFG All terrains also appeared to throw the most stones. The trailer stone guards on the vehicles fitted with BFG All terrains were heavily damaged. Incidentally, those vehicles were also the ones that smashed rear windows (Discovery and the 200 series). The stone guards behind other vehicles were only lightly damaged.

GOODYEAR MTR
http://www.aulro.com/afvb/members/pawky-albums-general+photos-picture5410-mtr-condition-2.jpg
http://www.aulro.com/afvb/members/pawky-albums-general+photos-picture5405-mtr-condition.jpg

COOPER ZEON LTZ
http://www.aulro.com/afvb/members/pawky-albums-general+photos-picture5409-cooper-ltz-condition-2.jpg
http://www.aulro.com/afvb/members/pawky-albums-general+photos-picture5408-cooper-ltz-condition.jpg

BFG ALL TERRAIN
http://www.aulro.com/afvb/members/pawky-albums-general+photos-picture5407-bfg-condition-2.jpg
http://www.aulro.com/afvb/members/pawky-albums-general+photos-picture5406-bfg-condition.jpg

STONE GUARD DAMAGE
http://www.aulro.com/afvb/members/pawky-albums-general+photos-picture5404-stone-guard-damage.jpg

Feel free to ask any questions you like about our vehicles, our setups, trip planning etc. I'll try to answer as many questions as possible. I've gotten so much great info off this forum over the years I am happy to try and give back a little.

[Tombie]

Well written and a good report for people to cogitate on...

[Eevo]

fantastic

[plusnq]

Thanks for that. Great write up.

[Ferret]

... when a shock absorber strut collapsed

Can you elaborate on the circumstances surrounding this please - what vehicle, where, contributing factors etc.

[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?

[PhilipA]

Can you elaborate on the circumstances surrounding this please - what vehicle, where, contributing factors etc.
Taking bets on 200 series.
I spoke to 2 owners at Drysdale who had broken shocks on the Mitchell Falls Rd.
The shocks are very short .
Regards Philip A
BTW the BFGs looked like my rears on my RRC after a similar trip, but I never rotated them. My D2 s are fine as I rotate them every 5K. Chipping is caused by rocks being thrown from the fronts onto the rears( according to Cooper) , so mudflaps in front of the rear tyres may help. Also I wonder if too low pressure was an issue.

[pawky]

The collapsed strut was on the 80 series. It is a well decked out truck (has been in 4wd action a little while ago) with all aftermarket suspension bits. I can't remember the brand of the struts but they were still under warranty and the damaged strut was replaced without question in Broome.

The 200 series has all aftermarket suspension too. No problems there.

The Disco's have all factory suspension. No problems there either :)

[pawky]

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?

In my experience the slower speed is much harder on the vehicle (it is not just about comfort). I don't debate that at whatever speed, the struts are working incredibly hard and those roads can only shorten the life of the struts. But if there is a speed at which the corrugations smooth out then I would go for it every time.

Airing down the tyres appropriately is also an important part of minimising vehicle and tyre damage.

[Disco Muppet]

Didn't the discussion about Greg Milner on here with the Vogue, who's air shocks failed due to severe overheating, point to slow speeds as being the likely cause of failure, as they were being frequently cycled without the cooling air flow that faster speeds provide?
Great report on the tyres, sounds like a fantastic trip.

Sent from my HTC One using AULRO mobile app

[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?

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.

[pawky]

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?

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.

[Eevo]

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

[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,

[pawky]

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

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.

[Ferret]

The collapsed strut was on the 80 series.

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

[rar110]

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

[scarry]

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,

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.

[aus86inch]

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

[LandyAndy]

"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?

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

[LandyAndy]

Great report pawky.
You have pointed out what is important on gravel roads,the need to air down and slow down on corrugations,especialy with low profile tyres.
Drive a 100km or so at 110kmh on a corrugated gravel road an feel how hot the tyres get,you cant hold your hand on them;););););).
Andrew

[shanegtr]

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

My theory is at higher speeds the tyres have minimal contact with the dirt at the low points of the corrugations. Your driving more over the top of them. So going by that train of thought your suspension would actually be covering less distance at speed compared to low speeds, however the velocity of the shock movement at higher speeds would obviously be higher. Would be and interesting thing to film with a high speed camera to see whats happening at various speeds

[Tombie]

Its been done... I'll have a look on Youtube..

Andy: Airing down is a catch 22 - theres so many variables... And with low profile can do more damage than good... And with high profile can induce heat and flex failures...

It all is a balancing act :cool:

[Tombie]

"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?

Rather the replaceable suspension than the entire vehicle shaken to pieces.

Hours of corrugations are extremely taxing on the vehicle and the occupants..

Usually - slightly lower tyre pressure and around 80-90km in a coil sprung vehicle tends to settle it down.

In a D4 you can really push that higher - although the safety of it is questionable... I have had the D4 and Camper well into triple digits on corrugations.... I dont recommend people try it...

At 80-90 the vehicle is 'skimming' the top portion of the corrugations giving enough control for most situations whilst avoiding the jarring of the lower portion...

I have been on a track though where the spacing was 300mm - nothing you can do there improves the ride...

[jonesy63]

So the KM2 was the only tyre to not be staked or get a flat. (Suspension failure destroying a tyre is hardly the fault of the tyre).

This mirrors my trip... I had no KM2 failures on my 2012 16,000km trip to the Kimberley, and I did a lot more gravel roads than this report.

:cool:

[winaje]

...I have been on a track though where the spacing was 300mm - nothing you can do there improves the ride...

Sounds like the corrugations caused by the harmonics of the trucks that use the Peninsula Development "Road" on the way to The Tip.

[Redback]

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.

Our KM2s on our D4 are almost shagged after only 20,000ks, I put ours down to always towing and rough gravel roads, I've always kept an eye on pressures, but I have to confess I don't always lower the pressures once we get to a gravel road, rather I'll wait till I get to camp, so having road pressure for a couple of hundred Ks on each trip(42 rear 38 front) probably did help.

Never had this issue on the D2 and we had 2 sets both were 50,000ks plus before going to our last set just before we sold the car and why we went with the KM2s for the D4, sadly not going to get anywhere near 50,000ks with this set.

Baz.