Literally the same day I shared that we’d be getting a set of the new Cooper Discoverer STT Pro tires for the 4Runner, I came home to a pile of fresh rubber waiting for me on the front porch (I’m sure the FedEx guy loves me…). Since then, we’ve wasted no time getting them mounted up and on truck, and we’ve already gotten a few insights on them from the install and handful of miles we’ve accumulated so far.
Initial Inspection + Install
Visually, the STT Pro’s look all business, with deep tread blocks, siping, sidewall biters, and scoops built into the tread blocks for mud traction. There is no mistaking this tire for anything but a serious off-road tire worthy of the most capable modern 4x4s.
One of the first things I did with the STT Pro’s was throw them on a scale to see how much they weighed since I had not seen any published specs from Cooper. In the 285/70/17 size that I’m running, these tires checked in at 60.6-61.9 lbs each, so a ~2.1% max variance, some of which might be attributable to the scale. As an aggressive load-range E tire, these STT Pro’s are coming in slightly heavier than the 58lb (published weight) Load-range D Goodyear MT/R’s that I am replacing.
Installing the Cooper STT Pro’s was no better (nor worse) than any other mud terrain tire. The tires are perfectly in-round and all 5 were easily balanced, however 2 of the 5 tires required more than 10 ounces of weight to get them into spec.
On-Road Initial Impressions
The first thing that hits you about the STT Pro’s is that they are QUIET compared to the MT/R’s. At a steady 50 mph (on the same stretch of road), I recorded a 10 decibel difference between the STT Pro’s and the MT/Rs. That’s pretty huge. I will say that the MT/R’s have gotten louder towards the end of their useful life, but they were never close to being as quiet as the STT Pro’s.
In terms of handling, the 4Runner tracks straight over road imperfections with the new tires and there are no unusual vibrations at highway speeds (which is something I experienced on the MT/R’s early on, before they “wore in”).
So far, with very limited experience, these STT Pro’s are checking all of the boxes. Now we just need to get them off the asphalt down to trail tire pressures and see how all of the innovative elements of these tires perform in the real (off-road) world!
More to come!
I just installed STT Pro’s on my Ram 1500. I am experiencing vibration at 50+ MPH. I have never done a M/T tire before is this normal?
A vibration that gets worse/more noticeable at high speeds sounds like a tire is not balanced properly. M/Ts will always be louder and transmit more vibration than A/Ts or passenger tires, but not to the extent you may be experiencing.
Just mounted STT pro 33/12.5/15 on our ’05 TJ/LJ a couple of days ago
– Absolutely great first impression,got them sipped extra
– 3″ of slushy snow all the way home ,50 mph ,temperature around the freezing mark.Very impressed in a good way
– curious how they stand up in the long run ?!
– used to run BFG M/T ( with additional siping )before,switched to Cooper ,only to save a few dollars upfront
Markus, sounds like you’re having a similarly great experience with the STT Pro. I’ve been running them well over a year now, and I’m impressed with how they are wearing, which is much slower than the Goodyear MT/R. At this rate I may get 50K+ miles out of them.
I sincerely, can say that your reviews are ones of the most professional I ever read. I had read a lot of reviews because I’m looking to change the factory tire set of my Xterra Pro-4X 2012. I just finished comparing BG good and Good year Wrangler in their AT and Mud versions. Also Firestone Destination and then I found Cooper Stt Pro. What can you say is the better for in between highways and off road use? All of them are expensive tires, which one to your knowledge has better value for what is offered?
Is this the all terrains?
The STT Pro is a Mud Terrain.
How many miles do you have on them now and what are your thoughts?
I have about 5,000 miles on the tires so far. I’ve covered a fair bit of my impressions of the tires in the linked posts below – check them out:
Tires still holding up good? Im on the fence with the STT or sticking with BFG MT for my 80, leaning towards the SST, at least there are some sipes on the tire….the BFG make my truck feel like its on Schwinn bike tires in the packed snow
Phong,
The Coopers have been great so far on the pavement and on some mild fire roads that we’ve run them on. Based on their design, they handle substantially better in the wet than the KM2’s. My KM2’s might as well be ice skates on hard pack, but they eat up the mud with the best of them.
If you’re on the fence I’d recommend the Coopers just because they’re the better all around tire.
Good to hear Bill Burke runs the STT’s. I have the Cooper ST/MAXX and have been very happy with them, though my next set will probably be the STTs. Both are heavy tires, but incredibly quiet on pavement, so if your rig does dual duty or is your daily driver, these Coopers are a good compromise short of having a dedicated set of trail wheels.
Were your sound levels with windows open or closed? I want to check to see how loud my Dick Cepek Mud Country tires are compared to your numbers. I have a set of the STT Pros on order, hope to have them installed before Overland Expo.
I had the windows closed. I figure that is the most relevant way to measure – making a reasonable move to reduce ambient wind noise and control for external sounds that may bias the measurement.
I have been running the STT Pro long term now and I’m totally impressed with the consistent handling. Some snow hit the high country recently and these tires did very well on the slick pavement. Didn’t have to pay extra for Sipe cutting either. You will be happy with those Coopers!!
Thanks for chiming in Bill! Always good to have a legend like yourself validate my initial assessment!
Why did you try something new vs the mtr’s I’m torn on what type of tire I want next, I don’t know if I should go with a mud tire or an AT tire again.
Adam, there’s a couple of reasons I decided to try something new. First is that I just like trying new products, and the STT Pros really got my attention with their tread design and features when they came on the market. The second reason is because I am hoping to find a tire that achieves almost all of the capability/durability of the MT/R in a slightly more liveable package (noise, winter weather traction). I put over 20K miles/year on the 4Runner and a whole lot of that is commuting and highway miles, so I do value a little bit of comfort while wanting absolute confidence in the traction/stability/stability of the tires when I do take it off road.