Cooper STT Pros reviews
06-13-2016, 04:43 AM
#41
JK Freak
I would call them an extreme condition all-terrain tire or a all-terrain/mud tire hybrid, not a true mud tire. What I noticed in mud/clay is that the inner and outer edge rows do clean clay with minimal speed (crawling) but the center 2/3 row stays full of clay. I did not do any spinning at speed to see if the center section would start to clean better because the tires kept pulling my up-hill in wet clay at Rausch Creek. There was no need to start getting wild with it.
They stick to rock very well. At 15 PSI they do not conform to rocks as well as the stock Rubicon 32" MT at 18 PSI, maybe I need to air them down more being a 37x13.5? But they stick to wet and dry rock surfaces at least as well, if not better, and I am leaning towards the better.
At almost 2K miles on them, they are just starting to "cut" or get that angle worn into the flat blocks, it is definitely time to rotate at 2K miles. Last night I measured with a tread depth gage and I am seeing 1/32" to almost 2/32" at the extreme worn off compared the new spare. My guess is that I'll run them 15-20K miles and sell them to replace with the same.
They stick to rock very well. At 15 PSI they do not conform to rocks as well as the stock Rubicon 32" MT at 18 PSI, maybe I need to air them down more being a 37x13.5? But they stick to wet and dry rock surfaces at least as well, if not better, and I am leaning towards the better.
At almost 2K miles on them, they are just starting to "cut" or get that angle worn into the flat blocks, it is definitely time to rotate at 2K miles. Last night I measured with a tread depth gage and I am seeing 1/32" to almost 2/32" at the extreme worn off compared the new spare. My guess is that I'll run them 15-20K miles and sell them to replace with the same.
06-13-2016, 07:30 PM
#42
I would call them an extreme condition all-terrain tire or a all-terrain/mud tire hybrid, not a true mud tire. What I noticed in mud/clay is that the inner and outer edge rows do clean clay with minimal speed (crawling) but the center 2/3 row stays full of clay. I did not do any spinning at speed to see if the center section would start to clean better because the tires kept pulling my up-hill in wet clay at Rausch Creek. There was no need to start getting wild with it. They stick to rock very well. At 15 PSI they do not conform to rocks as well as the stock Rubicon 32" MT at 18 PSI, maybe I need to air them down more being a 37x13.5? But they stick to wet and dry rock surfaces at least as well, if not better, and I am leaning towards the better. At almost 2K miles on them, they are just starting to "cut" or get that angle worn into the flat blocks, it is definitely time to rotate at 2K miles. Last night I measured with a tread depth gage and I am seeing 1/32" to almost 2/32" at the extreme worn off compared the new spare. My guess is that I'll run them 15-20K miles and sell them to replace with the same. <img src="https://www.jk-forum.com/forums/attachment.php?attachmentid=649611"/> <img src="https://www.jk-forum.com/forums/attachment.php?attachmentid=649612"/>
06-19-2016, 09:19 PM
#44
JK Super Freak
Got them in 37x12.5r17, love them. Best set of tires I have had next to the old cooper stts. Hardly any road noise, coming from KM2s which was a nice surprise considering how aggressive they are. Took them out on the trail right after I put them on and they did great in the mud. Balanced pretty good, and are much smoother than my old KM2s too. highly recommend them 
06-23-2016, 06:26 AM
#45
JK Newbie
Join Date: Jan 2013
Location: Oklahoma
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I'm about to take plunge to 37s with these tires. I'm just not sure whether to go with 12.5 or 13.5. How did you guys decide? Also anyone with significant long term use notice how much wear they are getting?
06-23-2016, 08:22 AM
#46
JK Freak
If you have a ram assist, you will not have an issue with the 13.5. If you do not, the 12.5 may be slightly better. It's a lot of tire to turn when your nose down in big rocks and the weight of the jeep is going to the front axle.
With that said, if you are more of an overland or trail kind of user, the 37" might be perfectly acceptable to you with just the steering gear box.
I went with an assist and 13.5" wide, not that I am a hard core rock smasher... but I do like to play in rocks now and again. With the ram assist it feels better than it did with the factory 32" BFG tires. I would occasionally get into positions where the steering was stuck and had to make an undesired move to try and get the steering to free up. Now with 37x13.5 and assist, I have not seen that happen at all.
It is one of things that you should be able to answer based on your type of terrain and your type of use.
Staying narrower will be slightly better for a stock set up, no doubt.