The Cooper Discoverer RTX merges innovation with versatility, as it aims to offer an unparalleled driving experience on both highways and light off-road terrains. Let’s see if this tire is made for you!
Table of Contents
Tire Sizes
The tire comes in 15 to 18 inches wheels. And all of those sizes have following specifications.
- Speed Ratings: R, S and T only.
- Load Ratings: SL, XL, C, D and E.
- Tread depth range: 12 to 17/32″.
- UTQG: 500 AB.
- Treadwear warranty: 50k miles.
Outer Construction
The Cooper Discoverer RTX tire has three ribs in the middle and slighter thicker lugs on the sides.
Let’s talk about the sides, where two things come, shoulders and sidewalls.
Now you might have noticed that there isn’t anything happening on the sidewalls, where the tire doesn’t have any lugs.
But shoulders on the other hand, form slightly staggered design with notches facing outwards, and interlocking siping.
Moreover, they also form irregular shapes, so there are a ton of off-set edges (which really help out off-road).
Moving towards the middle, there are 3 ribs there, again formed by very irregular lugs.
And here all these lugs are seen with notches facing both lateral sides, and full depth, slightly interlocking siping.
Moreover, these lugs are all connected to each other longitudinally, (a feature which greatly helps with the directional grip).
Inner Construction
When driving on rough and wild terrains, tires need to withstand tough conditions, where basically punctures can happen (mostly on sidewalls).
That’s why you’d won’t be impressed with the durability of Cooper RTX.
The tire for one, offers the average 2 layered polyester casing structure, (with two steel belts which are then finished off with two layers of nylon on top).
And of course, its missing with any lugs on the sidewalls, so no additional protection is there as well (and it does make a big difference, especially on rocks).
Highway Performance
Being an on-road oriented A/T tire, the Cooper Discoverer RTX does not disappoint when it comes to dry traction.
It performs well in every way, whether it’s grip on dry roads, quick steering response, or stable cornering.
Let’s talk about these main points below.
Dry Grip
The efficacy of dry grip hinges greatly on the extent of the tire’s contact with the road surface. Meaning, a greater contact area facilitates enhanced friction and consequently, better grip.
The Cooper Discoverer RTX excels in this regard, offering substantial rubber-road contact.
Moreover, the lateral grooves between the blocks are not mere “smaller” indentations but have reinforced foundations underneath. Meaning, all lugs are joined up to each other (longitudinally), from underneath.
Furthermore, the tire demonstrates significant lateral traction, courtesy of its closed and compact shoulders which are also joined up with what Cooper calls, whisper groove technology.
This tech basically joins up shoulder lugs, filling gaps between the lateral voids they make. And it besides improving lateral traction, also helps in limiting overall noise levels the tire generates.
Steering Response
The Cooper Discoverer RTX sets a high standard in steering communication, offering a near-instantaneous connection between steering input and feedback.
But how its able to do that being all terrain tire I mean?
Well, first you need to understand that as the tire corners, majority of the weight distribution goes to the sides of the tread, basically on shoulders. So how well they connect with the surface, is crucial.
Now, the Cooper RTX comes with pretty compacted up shoulder lugs, so they stay firm even on sharp corners.
Moreover, the tire is also pretty light, comparing other A/T tires, so those shoulder lugs don’t carry as much pressure on them, forming a improved over and under steer balance, and with it steering response.
Wet Traction
Achieving substantial wet traction can be a tough nut to crack for aggressive off-road tires. However, a handful of top-notch off-road tires (which are basically on-road oriented), excel in offering significant grip, and the Cooper Discoverer RTX stands among them.
(Other examples of such tires, include Cooper AT3, Sumitomo Encounter A/T and so on).
But what factors are at play here?
Well, there are two, tire’s ability to maintain grip on wet surfaces and its resistance to hydroplaning. Let’s delve into each aspect.
Wet Grip
The ability of a tire to hold onto wet roads is greatly influenced by the structure of its tread and the number and quality of sipes it has.
So unfortunately, the Cooper Discoverer RTX doesn’t shine in this regard.
It lacks an all-weather rubber compound, which is typically a blend of silica and modern tread technology, vital in enhancing the tread’s flexibility.
This flexibility is crucial for ensuring a strong grip on wet roads.
Basically sipes are responsible for dispersing water by drawing it into their slits. They expand and contract to create suction for the particles. And so with lacking flexibility in the tread, the Cooper RTX isn’t able to clear off water particles as effectively compared to other AT tires out there (comparable, I mean).
Hydroplaning
Hydroplaning happens when a tire can no longer grip the road and instead glides on a layer of water, so of course, when this happens, all traction is lost (as the tire is literally “floating”).
To counteract this, tires are designed with grooves in the tread that help in directing water away, preventing hydroplaning.
And this goes for our tire here as well.
The Cooper Discoverer RTX features wide, interconnected grooves that facilitate easy water passage, endowing it with good hydroplaning resistance and allowing it to maintain reasonable float speeds.
Side Note: If you’re not familiar with “float speeds,” it denotes the highest speed a tire can achieve on water-covered roads without losing touch with the surface, preventing it from “floating” or hydroplaning.
Winter Traction
Even though the Cooper Discoverer RTX doesn’t have the 3-Peak Mountain Snowflake (3PMSF) certification, it still manages to deliver noteworthy grip on snowy surfaces thanks to its all-season tread pattern.
In layman’s terms, this tire shines with its smartly designed grooves that are skilled at navigating through snow, backed by a structure that is great at basically picking up and trapping the snow.
This basically allows for snow-to-snow contact, an essential feature for maintaining grip.
And it works because snow sticks better to the trapped snow particles, compared to rubber of the tread.
However, it’s worth noting that the tire could use some improvement for handling extreme cold temperatures that cause the rubber to harden up. I mean, it lacks a thermally adaptive rubber compound, a feature prevalent in many other all-terrain tires available in the market.
Off Road Traction
Off-road, I tested the Cooper Discoverer RTX across a variety of terrains. So let me share how well they performed in each of them.
On Mud
Traveling through muddy areas requires tires with wide channels that can get rid of mud. Otherwise they would get packed, and mud to mud contact loses all traction, and maximizes slippage. So basically its the recipe for getting stuck, in other words.
Now in this regard, the Cooper Discoverer RTX may not be your best bet, especially if you’re planning to tackle deep muddy terrains.
The tire has longitudinally aligned ribs where lugs are joined up to each other, and this restricts the sideways flow (predominately) of the mud.
Moreover, the tire is also missing with proper staggered shoulders and mud scoops, which throw back the thick clay, generating forward moving inertia.
On Rocks
For rocky paths, you need tires that can grip from various directions and durability and the Cooper Discoverer RTX is lacking in both these areas.
Its longitudinally aligned ribs basically don’t allow lugs to bite in to the rocky surface effectively, and with missing biters, mostly notches, the grip is compromised further.
Moreover, the tire also lacks the needed durability, where its just 2 ply polyester with no sidewalls. So as already mentioned in the durability section, these tires get punctured pretty easily on aggressive rocky terrains.
And yes, with missing sidewalls, lowering air pressure isn’t helping either.
Basically reduced pressure offers additional tread content as the sidewalls flex, and spread out grabbing and pulling the rocky surface.
Check out air pressure guide: https://tiredriver.com/air-pressure-guide-for-all-terrain-tires/
On Sand
Moving on sandy surfaces can be notably tricky, mainly because of two vital factors: the tire’s structure and the amount of tread making contact with the ground.
Considering these elements, it’s clear that the Cooper Discoverer RTX struggles to keep a good grip, especially when it comes to deeper terrains.
And this issue arises from the lack of sidewall lugs and its sharper outer edges, causing the tire to be more prone to getting buried in the sand. And digging in sand means game over.
Though in tire’s defense, the Cooper Discoverer RTX’s lighter weight does help a little, especially when it comes to slopes.
Fuel Consumption
The fuel efficiency of a vehicle is significantly influenced by the rolling resistance of its tires, which is then affected by factors such as the tire’s construction, the composition of the tread, and its weight.
In this regard, the Cooper Discoverer RTX showcases commendable performance, largely because of its relatively lightweight build, relatively stiffer rubber composition, and compact tread blocks, setting it apart from many other all-terrain tires.
With stiffer rubber, lugs don’t flex too much, which wastes energy, and here the tire’s lighter weight also helps, as lugs don’t get to have as much pressure on them.
Moreover, with compact tread blocks, the tire ensures optimal weight distribution.
Ride Quality
While the Cooper Discoverer RTX’s rigid composition might fall short in soaking up bumps compared to other more aggressive options, its stability on the road and ability to dampen noise qualify it as a comfortable choice.
And this goes especially when considering that on-road stability constitutes a significant aspect of overall “comfort”, in my view.
And here, the stable and silent ride is attributed to the Discoverer’s enclosed lug design and firm composition which enhance steering responsiveness, and gives smaller area for the air particles to move and hit around producing noise.
Additionally, its pitch sequencing technology helps in minimizing noise further, where lugs are made with slightly varied angles, so that they can form different sound frequencies as air particles hit them (coming at numerous angles).
And this then cancels out the tones, dampening noise levels.
But its just a backup, as the main noise reduction happens at the source, as the tire features Whisper Groove Technology, a special feature from Cooper, which essentially involves the integration of connectors between the shoulder blocks, the area where most of the airflow occurs.
And so one can you noise is handled at the source in this case.
You can read more on it here: https://tiredriver.com/are-all-terrain-tires-noisy/
Tread Life
When it comes to tread longevity, Cooper RTX doesn’t exactly impress. And its not surprising given its relatively low UTQG (Uniform Tire Quality Grade) rating of 500, which is somewhat below average.
For a frame of reference, you might look at the well-regarded Toyo AT3 (review), a popular all-terrain tire known for its long-lasting tread, which gives you a UTQG rating of 600.
Nonetheless, it should be noted that Cooper RTX does comes with a generous 50,000-mile warranty still, (available for all sizes).
Take Home Points
So overall, it all comes down to this.
The Cooper Discoverer RTX is a versatile tire that handles well on both highways and light off-road terrains, offering strong dry grip and responsive steering due to its well-designed lugs and ribs.
It provides reliable wet traction and decent snow grip, despite lacking a 3PMSF rating.
And its performance is somewhat mixed off-road, excelling on rocky terrains but struggling on sandy and muddy surfaces due to limited sidewall lugs.
Moreover, the tire ensures a quiet, stable ride, though its firm composition compromise a little when it comes to subjective comfort.
What else? Yes, while it showcases great fuel efficiency, its lower UTQG rating indicates a potentially shorter tread life, though you still gt 50,000-mile warranty.
