Review of Cooper Discoverer ST/Maxx

*February 10, 2017 Update

With 30,000 miles on the tires now — I can confirm that the expected life of these tires is in the 35,000-40,000 mile range (down to ~4/32nds). Since installation they’ve had five alignments, well maintained air pressure, and a rotation and balance every 6,000 miles.

Also of note is the significant increase in road noise as they’ve worn. Still nothing when compared to a mud terrain, but loud when compared to them rolling off the rack new. But beyond being a faster wearing tire that gets louder with age — it’s still the toughest and best all terrain tires I’ve ever used (no flats, punctures, tears or cuts!). In fact, I’ve replaced them with another set, but in a larger size.  

I did a ton of research before replacing the OEM tires on Sebastian. And I made a poor choice. So when it came time to replace those, I did even more research (is that possible?!?). The road-tailored A/Ts weren’t cutting it — but I wasn’t about to compromise so much as to go M/T. I looked hard at the Goodyear Duratracs, Toyo R/T, and the more aggressive A/Ts (BFG KO2, Grabber A/T2, etc.). But there was one tire I kept coming back to… and in all my research could only find one negative review about. That tire was the Cooper Discoverer ST/Maxx.

DSCN2765

Background

We just finished a 3,500 mile overland trip with a ton of pavement and a little dirt, mud, snow, rain, granite, slick rock, sand, and all the combinations in between. I have a short commute to work on pavement, but wander off into the dirt, sand and rocks every week to run, bike, fish or a little of each. And occasionally (not quite monthly) we go on some sort of road trip with a good amount of off-road driving. The issues with both the OEM and replacement tires was durability. They had their issues, but primarily I couldn’t keep from loosing treads or cutting sidewalls.

Enough about me, back to the Coopers!

I really, really like them. Far and away the best tire for my needs (but maybe not yours). Let’s look at them from installation to today.

Installation

These were a really tough tire to find in Southern California; making negotiating on price almost impossible. And the 255/85 size is/was on national back order. All that said, they’re a reasonably priced premium tire. I actually walked away with them installed for less than what I spent on my last set of tires.

DSCN2764

They measure tall for a 265/75 (full 32″) and come with gobs of tread made from a natural rubber and silica compound. Definitely a softer tire, so I expect them to wear on the quicker side. Once installed I did have trouble balancing them. They did balance out without a road force machine, but it took a couple tries. I think this is less of a tire issue and more of the short wheel base combined with a 53 pound tire (it’s heavy!) with speeds over 70 MPH.

And that weight has it’s cost. On the highway, I saw no drop in MPG. Nor did I off-road. However, I did see about a half-MPG drop in town. Starts and stops with that heavy tire take their toll. I also felt that weight just ever so slightly in braking and acceleration.

Siping isn’t great, but it’s good for the class of tire this is in. Usually one of my criteria for a tire is the mountain snowflake… so I made a compromise to my own rules with the Coopers. But, where I didn’t compromise (and glad I didn’t), is the three ply sidewall. There aren’t many tires left with such insurance. And according to Cooper, their Armor-Tek3 sidewalls are stronger than the competitors 3-ply sidewall.

On the Road Again

On the road these are amazingly quiet for what they are. You can hear them starting at about 30 MPH up through 60 MPH. A slight hum, but no vibration and nothing like a mud terrain. Above 60 MPH I can’t hear any difference from any other tire I’ve had (proof of Sebastian’s aerodynamics). On the tire volume dial, they’re one-notch louder than a BFG KO… two-notches max.; and seven or nine notches lower than a BFG KM2.

In the rain they did great. I think this is mostly due to the rubber compound over siping (or lack there of). I had no reason to shake any confidence in the rain… but it’s not sticking like glue to the pavement like the Revo2, Triple Treads or Adventures. They’re “fine” in the snow… the deeper, softer stuff is best and the closer it gets to ice the worse the the tire gets. I’d say they’re slightly below average for an A/T in the cold stuff — but leagues better than an M/T.

They’re also a smooth rolling tire with a soft ride. It’s the only Load E tire that doesn’t make the Xterra ride like a covered wagon. On-road, this is 90% A/T (win!).

Off-road

These tires have some serious bite off-road. Aired down to 25 psi they had almost no wheel spin on steep slick rock; with sidewalls and tread that deform well. Snow and sleet covered granite was slick — as expected — but honestly really good. Some of the conditions we encountered were down right terrifying and these Coopers held throughout the off camber rock crawling on exposed two-track.

DSCN2766

I was taken aback the first time we crawled — with no tire spin — through some sticky Utah clay (fell through the crust and into the muddy mess below) to find clean treads. This is a tire I’d honestly pit against some mud terrains. I’ve never seen anything like that except from a dedicated mud tire.

DSCN2763

In the drier stuff, sand and dirt, they track and ride well. Even at speed. They throw rocks and pick up a few… but I don’t think any better or worse than others I’ve seen. And after a highway drive the rocks are gone (which I can’t say about other tires). Off-road, this knocks the socks off any A/T you can stick under your rig.

Summary 

We completed our 3,500 trip without a single hiccup from the Coopers. No flats, punctures or cuts. Tread blocks intact without tearing. This trip I know would have shredded the tires they replaced. Are they louder than your average A/T? Yes. Will they last 50,000 miles? Probably not. Are they the best off-road tire I’ve driven without any real compromise on-road? Absolutely.