Cooper ST's - 255/85/16

[cjmitchell5]

Here's a couple bad pics w/ the new Discoverers mounted.

I'm still contemplating what I'm going to do about the front suspension, if I should leave it or level it.

 

[Redline]

Siping depth?

Jim,

Since you wore your first set down pretty low...

How deep is the factory siping on our Cooper ST tires? Full depth?

I know my Maxxis Bighorns only go down a few thirty-seconds on the outer lugs.

Thanks

 

[jim65wagon]

Some of the siping is still there. It's not full length, as the tire wears the siping gets shorter and shorter. Here is a pic of the ST with 6/32nds. (I just measured it - kept it for a spare) Ignore the thin, long sipes; I cut those with a razor knife last winter to make a snowy/icy road run up to the inlaws in NW PA.

 

[Redline]

Thanks for the update Jim!

 

[jim65wagon]

I'd just like to update this a bit. I now have about 20,000 miles on my second set of ST's. This morning I got up to drive my wife to work in the 8 - 14 inches (depending on location, drifting etc) of snow. With my driveway being steeper than a house roof, I was a little concerned about getting the truck out. Needless worries...she climbed out with nary a spin, travelled some unplowed backroads effortlessly, and made it the 20 miles into FBurg. The ST's now qualify as great snow tires in my book.

 

[dnellans]

that really interesting that you decided you like them in the snow/ice. my ST's are nearing the end of their life and the only place i don't like them is on the snow!! i'm in utah and compared to my old bfg at's i just don't trust them to not break loose on icy stuff.

if i lived in a warmer climate i would do them again in a heartbeat, but i suspect i'm going to go from the 255/85 ST's back to 235/55 bfg ATs since they don't make a 255/85 size... i was previously running 265/75 bfg ATs and would like to go less wide this time i think.

 

[tacollie]

I love mine in the snow. They are ok in the ice. I am considering having the center lugs siped. My only real grip is they don't hook up well on wet pavement.

 

[Runt]

Interesting....my only complaint with the 255/85/16 ST is they are not good in snow and ice. I even have mine studed. I live in Northern British Columbia Canada so I drive ice & snow for 7 months a year. I have owned many sets of snow tires between work trucks and my vehicles and the ST is one of the worst I have used. The performance becomes horrible at around -15 degrees celcius as the rubber seems to freeze at that tempature. Other than that there a pretty good all terrain. I hate them for winter tires.

 

[jim65wagon]

Funny how different people have different perceptions. I'm sure it's a combination of perceptions and differences in weather patterns. I know the snow we get in Virginia is different than the snow we got in Pennsylvania. What we got in VA over the weekend was fluffy on top with a nice compressible base, and the ST's were really able to dig in and go. The temps here are running 27-34 degrees F (-2 to 2 degrees C?) and that's fairly normal winter temps. As far as ice goes I don't think the ST's were any worse than the BFG ATs I've had in the past.

 

[john difool]

put mine on the 80

just had mine mounted lately. like em so far. haven't had the chance going off the pavement yet tho. attached some pix.

 

[tacollie]

Maybe psi or driving styles affect how we all feel about tires. I have been in plenty of driving conditions at -15C and colder the last few weeks and no complaints, but I am coming from mud terrains. I don't have enough experience with bfg ATs in the winter. I had them for 2 months one summer and hated them. They just didn't hook up on the loose terrain around here.

 

[Redline]

Unquestionably! All variables matter from the PSI, vehicle, modifications, driver, you name it. My view is that the most valuable opinions are the ones which compare different tires on the same vehicle, with the same driver and in similar terrain.

 

[Larry]

I got about 4,000 miles on my 255/85/16 ST's and still like them. Seem to work great in the snow we had recently.

 

[Redline]

jim65wagon snip.......

as an aside, which do you like better; the FCII's or the ST's?

I'm answering this question from Jim here because it seems like a better place to comment and share.

Having driven on ******** Cepek Fun Country II 285/75R16 tires exclusively for the past 6-months I have come to really like the FCII tires. Though there is one thing I don't really care for and can't change, they are 285s and I much prefer a 255/85, particularly for traveling on-road. Off-road the FCII were Very Good.

The short answer to Jim's question is that I easily like the FCII more if it was merely a question of which tread design I prefer. However, there is more to it than that. How these two tires in their respective sizes actually motor down the highway when on my 4Runner is what matters most to me unless I start exposing weaknesses. The Cooper S/Ts win in this contest on my car. The narrower tire tracks straighter.

One might observe that both tires are cross-over or compromise designs. Agreed. The S/T has a bit more void and noise, the FCII has more siping and better winter tractio.

The Cooper S/T (Sure Trac)

After going for a Saturday afternoon MPG test and odometer error confirmation drive yesterday I had a few thoughts on the S/T.

They are not the most:

Aggressive
Heavy-Duty (only 4-ply tread, 2-ply sidewall, & the sidewalls are very exposed for a 255/85 size)
or Quietest

They are also not the most expensive. Retail prices can be quite high but OnlineTires.com currently has them for less than $150.00 each plus shipping (about the same as the Maxxis Bighorns in 255/85).

Though the Cooper S/Ts have never been my primary off-highway tire, they have done a few off-highway miles and I've yet to pop, puncture, or even cut one. Maybe I need to use them harder and see what happens, though I am a little concerned about the exposed, soft sidewalls.

While they are not quiet, they are quieter and more civilized than the Maxxis Bighorns, BFG MT KM, and KM2 in 255/85, and MT/Rs in 285/75. They run down the road very well and wear seems to be good unless you cut/chunk them on the rocks.

I guess what is most telling is that while the Cooper S/Ts have never been my favorite tire, they have stayed in my garage for a couple years while other treads have come and gone for a variety or reasons. They have staying power.


Edit March 2011: All of the above about the Cooper Sure Trac is still valid, but another year has passed I'm an even bigger fan of the ******** Cepek F-C II tread.

 

[tacollie]

In my opinion the coopers are a good all around tire. They handle everything well for the most part. I had them siped last week and that really helped on ice and snow, but they still don't hook up well on wet pavement. I actually preferred my BFG KMs with the center lugs siped over the Coopers.