Cooper ST's - 255/85/16

[SOAZ]

Adding to the info in this thread, here are a couple shots of the supper narrow Cooper STs stacked next to Maxxis Bighorn MT. Both tires are 255/85R16 and both are mounted on Toyota TRD FCJ 16x7.5-inch wheels.

The Coopers are noticeably narrower, but mostly in the tread. The Cooper ST has a tread of about 7.2-inches while the Bighorns have about 7.75-inches of thread width. I like them both ☺ The Coopers were temporarily removed to run the quiet Maxxis Bravo ATs.

Nice shots! Tread is similar. Are the maxxis's that much quieter.

 

[Redline]

I would like to do a back-to-back highway noise test over specific roads at set speeds to analyze noise. But...

The Cooper STs are quieter than the Maxxis Bighorns, particularly at higher, freeway speeds. At lower speeds in town they both make noise (a howling, rumble).

Looking at these treads side-by-side one sees that the Cooper ST has more void in the center of the tread compared to the Bighorn, but the ST has less void along the outer lugs.

Nice shots! Tread is similar. Are the maxxis's that much quieter.

 

[R_Lefebvre]

Hey guys, newbie here, and somewhat new to trucks but thought I'd have some input in this. I recently bought an 04 Disco that came with 18's and highway tires. I traded those for a set of 16's and needed new tires so I went to get some ST's. Turns out they gave me ST-C's for the same price, I understand the C's are normally about $40 more.

I haven't experienced any other AT tires, but I was surprised at how much tread noise these have. It's not terrible, but the tire shop told me there would be none at all, which just isn't the case. It's not too bad however, probably because the Disco has good sound deadening.

I was concerned when I realized I got the C's because I wanted these to be my all season tires and I live in Canada. I thought the harder rubber wouldn't be good in ice and snow.

However, I have to say I'm reasonably impressed. As a little background, I've been more of a sportscar guy in the past, I used to rally a VW on Blizzaks, did some ice racing, etc... so I know snow. I also had a WRX with Dunlop Wintersports on them for comparison.

I can say that these tires really impress me for what they can do while not having a "Severe Snow" rating. I'd say overall they are comparable to the Wintersports on a car, which is a snow tire, not really an ice tire, but does have a severe snow rating. I won't hesitate to use these tires in the winter up here.

Sure, it's not as good as a 2000lb car with Blizzaks. But for getting around, they're pretty good. If I lived further north where there is more ice, I might have rethought them. For sure they are MUCH better than most "all season" tires such as the 18's that came on the truck (those were brand new Michelin Synchrones).

The size I bought is 245/75/16 which was as big as I thought I could go without lifting. I'd have preferred 265/75, but oh well. These are installed on what I believe are 8" rims, which reading here, would appear to be a problem. All I can say is the installers had no trouble at all, at least not that they told me. I actually prefer this setup for onroad handling, as it adds some stability to the sidewall. When they are pinched in, the tire can roll around on the rim much more. I want to tow a car hauler with this thing, so road stability was important to me.

As for the ride, I think it's excellent. I really can't differentiate it from the 18" highway tires that were on before. They seem to be perfectly round and balanced, though it appears they had to use more lead than I'd normally see on car tires. The truck runs smooth, though I do pretty much stay under 70mph.

I think I chose these for the same reason as everyone else. I wanted more than most AT's can offer, but no going to MT's. Personally, I think they're a great compromise. I haven't tested them yet off-road, but I can see they're highly thought of, and I don't have any issues with them on the highway other than the noise, which really isn't bad. For perspective, the overall cabin noise is still the same or less than most economy cars anyway.

After viewing those pics of the chipped tires, and giving these a shot in the snow, I'm glad I got the C's.

 

[SOAZ]

Hey guys, newbie here, and somewhat new to trucks but thought I'd have some input in this. I recently bought an 04 Disco that came with 18's and highway tires. I traded those for a set of 16's and needed new tires so I went to get some ST's. Turns out they gave me ST-C's for the same price, I understand the C's are normally about $40 more.

I haven't experienced any other AT tires, but I was surprised at how much tread noise these have. It's not terrible, but the tire shop told me there would be none at all, which just isn't the case. It's not too bad however, probably because the Disco has good sound deadening.

I was concerned when I realized I got the C's because I wanted these to be my all season tires and I live in Canada. I thought the harder rubber wouldn't be good in ice and snow.

However, I have to say I'm reasonably impressed. As a little background, I've been more of a sportscar guy in the past, I used to rally a VW on Blizzaks, did some ice racing, etc... so I know snow. I also had a WRX with Dunlop Wintersports on them for comparison.

I can say that these tires really impress me for what they can do while not having a "Severe Snow" rating. I'd say overall they are comparable to the Wintersports on a car, which is a snow tire, not really an ice tire, but does have a severe snow rating. I won't hesitate to use these tires in the winter up here.

Sure, it's not as good as a 2000lb car with Blizzaks. But for getting around, they're pretty good. If I lived further north where there is more ice, I might have rethought them. For sure they are MUCH better than most "all season" tires such as the 18's that came on the truck (those were brand new Michelin Synchrones).

The size I bought is 245/75/16 which was as big as I thought I could go without lifting. I'd have preferred 265/75, but oh well. These are installed on what I believe are 8" rims, which reading here, would appear to be a problem. All I can say is the installers had no trouble at all, at least not that they told me. I actually prefer this setup for onroad handling, as it adds some stability to the sidewall. When they are pinched in, the tire can roll around on the rim much more. I want to tow a car hauler with this thing, so road stability was important to me.

As for the ride, I think it's excellent. I really can't differentiate it from the 18" highway tires that were on before. They seem to be perfectly round and balanced, though it appears they had to use more lead than I'd normally see on car tires. The truck runs smooth, though I do pretty much stay under 70mph.

I think I chose these for the same reason as everyone else. I wanted more than most AT's can offer, but no going to MT's. Personally, I think they're a great compromise. I haven't tested them yet off-road, but I can see they're highly thought of, and I don't have any issues with them on the highway other than the noise, which really isn't bad. For perspective, the overall cabin noise is still the same or less than most economy cars anyway.

After viewing those pics of the chipped tires, and giving these a shot in the snow, I'm glad I got the C's.

Thanks for posting. Good info.
I think the ST's need to really be abused to chip, but I like the sound of the ST-C's. Similar tread depth and design, but a harder compound to resist chipping.

I actually sent an email to Cooper Tires urging them to make the st-c in a 255-85-16. I know it wont get them too, but you never know if others have sent a similar email.
Keep us updated on how the st-c's wear. Those may be my next set of tires someday.

 

[Redline]

What size would you change to if you were to go with the chip resistant compound?

285/75R16?

235/85R16?

Thanks for posting. Good info.
I think the ST's need to really be abused to chip, but I like the sound of the ST-C's. Similar tread depth and design, but a harder compound to resist chipping.

I actually sent an email to Cooper Tires urging them to make the st-c in a 255-85-16. I know it wont get them too, but you never know if others have sent a similar email.
Keep us updated on how the st-c's wear. Those may be my next set of tires someday.

 

[SOAZ]

What size would you change to if you were to go with the chip resistant compound?

285/75R16?

235/85R16?

If I did it would be to the 285's over the 235's.
The move to the st-c's would be out of practicality, but the choice in size would be for looks, ground clearance and because I have 4.88 gears on the way.
All in all, I'd love to see a set of 255-85-16's in the st-c's. Or maybe even a set of 34x10x16's, but we'll see what the future brings. I haven't ever seen a pic of the st-c's in the 285 size on a truck.

 

[R_Lefebvre]

My guess is that the ST-C is more of a commercial or "overland" application. That's why they're not making them in the larger sizes. I think the figure most people going for 32"+ are going to be getting mudders anyway?

Anyway, too bad, when I worked a Ford a few years ago, Cooper Standard was a supplier and I had access to cheap factory blemish tires. Never picked any up though.

 

[Redline]

Me too. As much as I like the 235/85R16 size, I prefer both a 33-in tall tire and load-range-D.

If I did it would be to the 285's over the 235's.
The move to the st-c's would be out of practicality, but the choice in size would be for looks, ground clearance and because I have 4.88 gears on the way.
All in all, I'd love to see a set of 255-85-16's in the st-c's. Or maybe even a set of 34x10x16's, but we'll see what the future brings. I haven't ever seen a pic of the st-c's in the 285 size on a truck.

 

[R_Lefebvre]

Why the D?

I was worried being this is my first truck, and everybody said that LT tires would ride really rough, especially the E load, but I think they're fine. Probably largely depends on on the vehicle too, but the Disco has a nice suspension to start with so it helps.

 

[Redline]

It all depends on your ride preference and sensitivity.

There are many variables; the tire tread/sidewall design and construction, the PSI used, vehicle suspension, but E-range tires will generally ride firmer than a load range D tire. I prefer a softer, more compliant ride and I have found D-range LT tires tough enough. A softer, lower load range tire will often flex and conform better when aired down.

One very high quality, heavy-duty tire that is very tough but doesn't flex/conform as much as I would like until it is aired down very low is the LR E Toyo M/T. Very stiff sidewalls and tread (I have owned the 265/75R16E, 285/75R16E, 255/85R16) until aired down to 10 PSI, where most of my other 255/85R16 load-range-D tires have done fine at 15-PSI on the same 4x4 trucks.

In the case of the Cooper STs in 255/85, I find it one of the smoothest/softest riding tires I have owned in this size. Wether it's rugged enough for ones purpose is another matter that we all need to decide, but I don't usually have a problem popping or poking holes in tires. It just depends on what you need from your tires.

 

[bigreen505]

For what it's worth, I'm running a 235/85 Cooper M&S E-rated on a Trooper and they are not too stiff, but they are fairly new. Comparatively I would say they are more supple than the 285/75 D-rated private label Coopers. I think this may have something to do with the 7" rim and that the 85-percent aspect ratio gives a fairly tall sidewall to squish.

 

[madizell]

Tall tires, such as 85 aspect ratio tires, aired down to the 8 to 10 pound range, will deflect from the center line of the rim a great deal in off camber situations, which can lead to bead separation, and can also change the vehicles effective center of gravity unexpectedly. At the very least, they would tend to wander around on the trail.

I don't believe that there is a perfect tire. You need to decide where you drive the most, what you want your tires to do the best, and buy accordingly. If you tend to run really low pressures quite often, i.e., 12 pounds or less, wide tires are easier to live with especially if mounted on slightly narrower wheels than recommended, which helps hold the bead intact. For a long time, I ran 33x12.5x15 Swampers on 8 inch rims and no bead locks, ran down to 8 pounds regularly on the trail, and never lost a bead. These, too, tend to wander around a bit when aired down, but not as much as would a 235x85x16 aired down to the same 8 pounds.

 

[Redline]

Yep, I have done (lost the bead) this on my F350 in Moab, Poison Spider Mesa trail, trying to go up the 'Wedgie' sidehill

 

[p1michaud]

Cooper ST Snow run report.

Today I had to opportunity to go out with two other rigs:

1. Jeep TJ, 4.88 gears, locked front and rear on 35" MTR tires - better than 85% remaining thread.
2. Jeep TJ, stock gears, locked front and rear on 33" x 12.5" Dirt Digger tires (I think) - better than 90% remaining thread.
3. Extended Cab Tacoma, 4.56 gears, locked front and rear with the 255/85R16 Cooper ST tires - better than 95% remaining thread.

Conditions:

• Trail conditions varied from rock, mud, to ice and snow (1" all the way up to 36" deep). The snow was the heavy and wet. Temperatures were right arround the freezing mark.
• 3rd vehicle down the trail.
• Aired down to 18 psi.

Here are my impressions. The Jeep on 35" was pretty much going anywhere he pointed it with a bit of throttle and back and forth when required. The Jeep on 33" was having a harder time in some places, we nearly turned arround at one point but I convinced him to use my chains, then he was ok.

The Coopers would not track as straight in the tracks left by the wider tires. They would cause my rig to wander side to side going down the trail (not desirable in the very tight trails we were on, actually cause the rear of the truck to brush up agains a tree at one point). I would say that their side traction is not the best I've ever experienced. However, they did go everywhere I pointed them at times digging all the way down to solid ground for traction. Often the truck would be bouncing as the tires were fighting for traction, I would simply stop back up and try again with a bit more throttle and the Coopers would find traction. In today's conditions I have to say that the Coopers totally surpased my expectations. My two Jeep buddies even commented on how well such a narrow tire performed.

To top it all off, on our way out we came accross a stuck truck that had slid off the trail into the deeper snow. I drove right arround him, used my new ARB snatch strap and after a few good tugs managed to get him back on the road. He wanted to pay me, but I said no instead the next time you see someone stuck, stop and help them out.

The Coopers now get an A+ for snow performance from me.

I'm still happy with these tires.
Cheers,
P

 

[R_Lefebvre]

P, I was just wanting to post similar observations on mine. After spending more time driving on them in the snow, I have to say their lateral stability (side to side) is lacking. They accelerated and stop well, but they don't track so well side to side. I also found the wandered a bit. At one point it resulted in my putting the right side on the soft shoulder, and it actually took a bit of effort to steer back onto the road.

I then drove my wife's Focus wagon with Dunlop Wintersports in the exact same conditions and there was no comparison. Her car is the model of stability. Easily able to maintain the speed limit in the worst conditions. I was going about 20k slower in the Disco.

Of course, the same is true when I had my Subaru WRX. Even with winter tires, the WRX was no match for the Focus in terms of getting somewhere safely. If you wanted to go fast, the WRX was fun, but getting somewhere safely it was no match. So it's not to say the Disco performed poorly, but it's got a high standard to match compared to our Focus.

I think the ST's will go anywhere, slowly. But they aren't dedicated winter tires.

Oh, and last week during another snow storm, I happened upon a large delivery van stuck in the snow on the side of the road. I had no trouble pulling him out in 4x4 low range and these tires. So like I'm saying, these tires have tons of traction, just don't let it get to your head and go too fast.