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Dunlop Grandtrek ST30 vs Cooper Discoverer AT3 XLT — Compared

Relative Score (0–100): 60% professional tests, 40% owner reviews.

Discoverer AT3 XLT is ahead, 76–52

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Tire BCooper

Discoverer AT3 XLT

Premium Touring All Season tire

Tests – · none yet Owners 80 · 800 reviews

“Cooper Discoverer AT3 XLT Picked up a set of Discoverer AT3 XLT from simple tire. With the 4th of July discounts all 4 were under 1k before taxes. I had the AT3 4S on a previous ram and they held up so I’m expecting good things here.”

Category by category

Relative Score per category, 0–100. Open “Why this score” for the tests and owner ratings behind it.

  1. 53

    Dry

    Discoverer AT3 XLT +25
    78
    Why this score
    SourceGrandtrek ST30Discoverer AT3 XLT
    Reviews found online4584
  2. 54

    Wet

    Discoverer AT3 XLT +26
    80
    Why this score
    SourceGrandtrek ST30Discoverer AT3 XLT
    Reviews found online4884
  3. 54

    Snow

    Discoverer AT3 XLT +16
    70
    Why this score
    SourceGrandtrek ST30Discoverer AT3 XLT
    Reviews found online4470
  4. 55

    Comfort

    Discoverer AT3 XLT +19
    74
    Why this score
    SourceGrandtrek ST30Discoverer AT3 XLT
    Reviews found online4280
  5. 54

    Noise

    Discoverer AT3 XLT +18
    72
    Why this score
    SourceGrandtrek ST30Discoverer AT3 XLT
    Reviews found online3480
  6. 51

    Treadwear

    Discoverer AT3 XLT +21
    72
    Why this score
    SourceGrandtrek ST30Discoverer AT3 XLT
    Reviews found online4277
  7. 46

    Handling

    Discoverer AT3 XLT +32
    78
    Why this score
    SourceGrandtrek ST30Discoverer AT3 XLT
    Reviews found online4678
Scores at a glance
CategoryDunlop Grandtrek ST30Cooper Discoverer AT3 XLT
Relative Score 52 76
Dry 53 78
Wet 54 80
Snow 54 70
Comfort 55 74
Noise 54 72
Treadwear 51 72
Handling 46 78

Higher is better. The Relative Score follows your weights below; category scores do not change.

Weight the categories that matter to you

Wet grip and treadwear start at “Important” — the two things buyers rank highest. Move the sliders and the scores update instantly.

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Recomputed
Headline score

Grandtrek ST30

Discoverer AT3 XLT

Pros, cons & observations

Themes extracted from owner reviews found online — not the opinion of TireWheelGuide.

Tire A Grandtrek ST30

Pros

  • Strong dry-pavement grip and straight-line stability
  • Competitive price point and value for money
  • High mileage potential for some drivers

Cons

  • Poor wet-weather performance and susceptibility to aquaplaning
  • High levels of road noise on various surfaces
  • Inconsistent tread life, with reports of rapid wear
All owner themes in the Grandtrek ST30 review

Tire B Discoverer AT3 XLT

Pros

  • Significantly lower road noise than comparable aggressive all-terrain tires
  • Excellent wet weather, snow, and slush traction
  • Sturdy sidewalls and stable performance when towing heavy loads

Cons

  • Some users report difficulty with balancing, leading to vibrations or a rough ride
  • Tread life occasionally falls short of expectations for certain drivers
  • Can struggle or get gummed up in deep mud
All owner themes in the Discoverer AT3 XLT review

What real owners are saying

From Reddit, forums and review threads. Not part of our score

Tire A

Dunlop Grandtrek ST30

We haven't collected enough community discussion about this tire yet.

Tire B

Cooper Discoverer AT3 XLT

Positive

Community opinion of the Cooper Discoverer AT3 XLT is overwhelmingly positive, with users frequently praising its smooth ride quality, exceptional quietness on the highway, and long-term durability compared to competitors like BFG KO2 and Toyo Open Country. Drivers also appreciate its solid value and performance when towing. A few users occasionally confuse the M+S marking with the Three-Peak Mountain Snowflake rating for severe winter conditions.

r/NissanTitan ·29 upvotes ·2023-03-29

“Put some new tires on the XD today. Cooper Discoverer AT3 XLT in 275/70R18. I usually run BFG KO2s on my trucks but wanted to try something different this time.”
r/Offroad ·1 upvote ·2025-10-02

“I’ve run Hankook dynapro’s, BFG ko2, Nokian outpost nat, and fallen wild peaks. Currently running Cooper discoverer AT3 XLT - they are definitely the quietest all terrains I’ve had. I would recommend them if they are available in your size - many places like simpletire or priority tire carry them.”
r/f150 ·51 upvotes ·2021-12-30

“New shoes this week, Cooper Discoverer At3 XLT. I’m really impressed so far.”
Top themes
#ride comfort#low road noise#tread longevity#winter and snow ratings#comparison to competitors#pricing and value#towing performance

Based on 8 community posts

Specs side by side

Attribute A · Dunlop Grandtrek ST30 B · Cooper Discoverer AT3 XLT
CategoryAll SeasonPremium Touring All Season tire
Vehicle typeSUV and 4x4SUV and 4x4
Sizes available54
Rim diameters17″ – 19″16″ – 20″
Tread depth10/32″16 - 18/32″
UTQG360 A A—
Treadwear warranty—60,000 mi
SidewallBlackwallBlack Side Wall - Raised White Lettering
Max pressure51 psi35 - 80 psi

Which one should you actually buy?

Dunlop Grandtrek ST30

Cooper Discoverer AT3 XLT

Winner: Cooper Discoverer AT3 XLT — better handling, wet and dry. It leads or ties in every category we score.

Pick tire B You enjoy sharp, responsive handling

Cooper Discoverer AT3 XLT scores 78 vs 46 on handling.

Pick tire B Your priority is wet-weather safety

Cooper Discoverer AT3 XLT scores 80 vs 54 on wet.

Pick tire B You want the most grip on dry roads

Cooper Discoverer AT3 XLT scores 78 vs 53 on dry.

Pick tire B You want the longest tread life

Cooper Discoverer AT3 XLT scores 72 vs 51 on treadwear.

Tire A · Dunlop Grandtrek ST30
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Tire B · Cooper Discoverer AT3 XLT
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How do we compare tires?

Every category score blends two independent signals. 60% comes from professional tire tests (braking distances, lap times, noise measurements), each result compared with every other tire in the same test and newer tests counting more. 40% comes from owner reviews found online, adjusted for how generously each site rates. Both use one scale: the average tested tire gets 70, the best 100. When a tire has only one of the two, the missing half is estimated from the other and the score stays closer to average; with no road test and fewer than five owner reviews it gets no score yet.

Community buzz from Reddit and forums is shown for context only — it never changes the score.

76

Leads

Discoverer AT3 XLT

Amazon