Cooper STT Pro Tyres
 

After running the stock Goodyear Wrangler Silent Armour tyres for nearly 40,000km over some very rough terrain, they ended up looking like this:
http://www.ausjeepoffroad.com/forum/...pictureid=3757
All five have looked like this for the last year, and aside from painting the sidewalls with tyre paint, they were just starting to look a bit ratty. Time for UPGRADES!

After looking around at the offerings in the AT market (Cooper ST Maxx, Mickey Thompson P3, Bridgestone Dueler, BFG AT KO2), I started looking at a few of the more aggressive packages: Goodyear Duratrac offers a decent 70/30 tread (this was a really close second choice - I just couldn't come at the 2 ply sidewall); BFG MT KO, and the Cooper STT Pro - the new kid on the block. All were roughly in the same price range, and I wasn't about to squabble over $20 a corner when the only thing you need to keep moving out here in remote NT is reliable (inflated) tyres.

Being a relatively stock Jeep, I needed to make sure of several aspects - that the tyres were going to fit the stock wheels, that they would fit within the wheel well, that there would be no/minimal rubbing. After reading through a LOT of forum posts on here, the 285/70R17 was identified as the way to move forward.

Considering the big change, my wife and I decided to take advantage of the time the wheels were off the car and get them sandblasted and powder coated to match the bullbar and sliders - texture black. As this undertaking required the removal of the TPMS units, new valve stems had to be sourced in a hurry. My local dealership wanted to sell me these TPMS units as a single item - at a cost of $192.38 EACH. Fortunately, Stuart Murchison was just a phonecall away, and a quick over the phone transaction had 5x valve stems in an airbag and on their way to my door for less than $100.

Here is the final product mounted on the wheel (white lettering to the inside) and ready to go back on the Jeep:
http://www.ausjeepoffroad.com/forum/...pictureid=3761

and leaving the showroom floor:
http://www.ausjeepoffroad.com/forum/...pictureid=3762

First impressions are as follows:

- there is the faint hum that is the trademark of the mud terrain tyre , but not much of it - there is not enough noise coming from them that the air conditioner fan can't block out.
- there is less feel at the steering level for where they are on the road, an expectation of anything with over 15mm of tread when compared to the previous tyres of <5mm tread
- there is the slightest change in gearing when driving between 60-80km/h where the transmission can hunt for the appropriate gear for a second or two longer than normal, but this was also expected due to the increase in rolling diameter.
- the rolling resistance is negligible at road pressures (currently running 34-36psi around town), though its possible the Jeep does slow down a little easier with engine braking than it did prior to.

Next post: Driveway dimensions and kitchen window admiring

Driveway dimensions, fit and finish, and kitchen window admiring
 

The first few days, my wife got to break in the tyres driving some 100km of corrugated roads south of Alice Springs while I was out of town, and reported back with "they're really nice" "everyone else is jealous" and "they feel a bit splashy on the dirt road" followed by this picture:
http://www.ausjeepoffroad.com/forum/...pictureid=3763

Tyre pressures run on that occurrence were 25psi all round, and the 'splashy' feeling was likely due to the decreased pressures and operating speeds of likely around 100km/h on corrugations.

Back in the driveway, a good look around shows how the tyres sit in the wheel well. Please note: there is a Teraflex levelling kit installed and a Uneek4x4 bull bar attached (and the springs/shocks have had 40,000km of abuse), so dimensions may vary slightly for those that are completely stock and looking to fit these.
http://www.ausjeepoffroad.com/forum/...pictureid=3741
http://www.ausjeepoffroad.com/forum/...pictureid=3740

Things get a bit tighter for the spare, with added compression of the spare tyre rubber stoppers
http://www.ausjeepoffroad.com/forum/...pictureid=3736
very little room to move around the third brake light,
http://www.ausjeepoffroad.com/forum/...pictureid=3747
and even less room around the well space in the rear bumper - there is contact from the tyre at the lower right side on the rear bumper, but no vibration that I can see thus far.
http://www.ausjeepoffroad.com/forum/...pictureid=3735


Next Post: Flex and rub check

Flex and Rub early testing
 

Time to check clearances and see how these go over some uneven ground! I took a quick trip down to a local levee bank which is just the right size to flex out the Jeep in both directions to see maximum compression and droop of stock suspension (pardon the shameless plug for my local 4wd club here.. and here):
http://www.ausjeepoffroad.com/forum/...pictureid=3764

What I found was that there was a clear finger widths clearance around all components at lock steering, and at full suspension compression while stationary. That being said, it is unlikely that the clearance would be there if the bump stops were struck in anger, and likely there would be some amount of rubbing at speed but this is yet to be tested fully - I'll report back once I have some more data.
http://www.ausjeepoffroad.com/forum/...pictureid=3742
http://www.ausjeepoffroad.com/forum/...pictureid=3743

I drove around a little on the rocks at road pressures and found the grip exceptional, there was good feel at the steering off road, and I felt as sure footed as a mountain goat.
http://www.ausjeepoffroad.com/forum/...pictureid=3746

Next post: Mud! early testing

Mud!
 

As luck would have it, some rain fell a few days ago, and the normally very dry area of central Australia became suddenly a muddy playground, and I was immediately drawn back to the same place where the rub testing took place.

Some fun was had. Please indulge me, as I don't get to see mud all that often. Even a little bit is exciting.
http://www.ausjeepoffroad.com/forum/...pictureid=3760
http://www.ausjeepoffroad.com/forum/...pictureid=3758

Early impressions are that these tyres do EXACTLY what they are designed for. What I took notice of while out playing in muddy puddles, was the excellent ejection of mud from the tread blocks, something I felt to take a closer look at. One can observe that between the sizeable tread blocks there is some impressed dimples. These appear to create a air pocket that prevents the mud from sticking between the blocks, and allows for great ejection of particulate matter. I found myself comparing them to the dimples in a high end Japanese sushi knife:
http://www.ausjeepoffroad.com/forum/...pictureid=3765
http://www.ausjeepoffroad.com/forum/...pictureid=3766

This made the explanation of the 30 foot rooster tails of mud I briefly saw in my rear view quite understandable, and even more enjoyable.

Apologies for not going deeper into the mud, but I will endeavour to find some deep mud and drive it until it stops me. I'm taking it slowly at the moment as I'm getting used to having grip again. I'll add more mud information as I collect it. For now its home to pressure wash the day away under the watchful supervision of the boss.
http://www.ausjeepoffroad.com/forum/...pictureid=3759

Coming soon: Off-road grip and slip, high speed bitumen and dirt review, 'bush bashing' trailblazing along tracks not driven for over 50 years, river rocks and sand, shale and s&*( your pants ascending/descending.

Great review nt. I will take an interest in further comments on wear ect.

Keep the details coming!
theses look like really good tyres

Are they genuinely quiet on sealed roads? I'm impressed if they're barely louder than the A/C

Been reading lots of good feedback on these tyres.....which will probably be my next set.