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Cooper Discoverer AT3 LT vs Dunlop Grandtrek AT20 — Compared

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

Discoverer AT3 LT is ahead, 74–46

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Category by category

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

  1. 77

    Dry

    Discoverer AT3 LT +34
    43
    Why this score
    SourceDiscoverer AT3 LTGrandtrek AT20
    Reviews found online8329
  2. 79

    Wet

    Discoverer AT3 LT +37
    42
    Why this score
    SourceDiscoverer AT3 LTGrandtrek AT20
    Reviews found online8233
  3. 71

    Snow

    Discoverer AT3 LT +22
    49
    Why this score
    SourceDiscoverer AT3 LTGrandtrek AT20
    Reviews found online7336
  4. 72

    Comfort

    Discoverer AT3 LT +21
    51
    Why this score
    SourceDiscoverer AT3 LTGrandtrek AT20
    Reviews found online7534
  5. 71

    Noise

    Discoverer AT3 LT +14
    57
    Why this score
    SourceDiscoverer AT3 LTGrandtrek AT20
    Reviews found online7842
  6. 71

    Treadwear

    Discoverer AT3 LT +19
    52
    Why this score
    SourceDiscoverer AT3 LTGrandtrek AT20
    Reviews found online7442
  7. 70

    Handling

    Discoverer AT3 LT +36
    34
    Why this score
    SourceDiscoverer AT3 LTGrandtrek AT20
    Reviews found online7034
Scores at a glance
CategoryCooper Discoverer AT3 LTDunlop Grandtrek AT20
Relative Score 74 46
Dry 77 43
Wet 79 42
Snow 71 49
Comfort 72 51
Noise 71 57
Treadwear 71 52
Handling 70 34

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

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Headline score

Discoverer AT3 LT

Grandtrek AT20

Pros, cons & observations

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

Tire A Discoverer AT3 LT

Pros

  • Excellent towing stability with minimal sidewall flex under heavy loads
  • Surprisingly quiet and smooth on the highway for an all-terrain tire
  • Strong durability and wear resistance on rough gravel, rock, and dirt roads

Cons

  • Subpar performance in heavy snow, ice, or deep mud for some users
  • Occasional reports of balancing difficulties or initial cold-weather tire thumping
  • Isolated incidents of sidewall splitting or premature wear
All owner themes in the Discoverer AT3 LT review

Tire B Grandtrek AT20

Pros

  • Exceptional tread life and high mileage capability (often exceeding 40,000 to 60,000+ miles)
  • Comfortable, smooth, and quiet ride on tarmac and highways
  • Good stability and predictable handling in dry, warm weather conditions

Cons

  • Extremely poor and potentially unsafe traction on wet roads, leading to sliding and long braking distances
  • Unreliable or hazardous performance in winter conditions like snow and ice
  • Subpar off-road capabilities, including low puncture resistance on gravel and poor traction in mud or sand
All owner themes in the Grandtrek AT20 review

Specs side by side

Attribute A · Cooper Discoverer AT3 LT B · Dunlop Grandtrek AT20
CategoryPremium Touring All Season tireAll Season
Vehicle typeSUV and 4x4SUV and 4x4
Sizes available149
Rim diameters16″ – 18″15″ – 18″
Tread depth16 - 17/32″—
Treadwear warranty60,000 mi—
SidewallBlack Side Wall - Raised Outline White LetteringBlackwall
Max pressure50 - 80 psi—

Which one should you actually buy?

Cooper Discoverer AT3 LT

Dunlop Grandtrek AT20

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

Pick tire A Your priority is wet-weather safety

Cooper Discoverer AT3 LT scores 79 vs 42 on wet.

Pick tire A You enjoy sharp, responsive handling

Cooper Discoverer AT3 LT scores 70 vs 34 on handling.

Pick tire A You want the most grip on dry roads

Cooper Discoverer AT3 LT scores 77 vs 43 on dry.

Pick tire A You drive through snowy winters

Cooper Discoverer AT3 LT scores 71 vs 49 on snow.

Tire A · Cooper Discoverer AT3 LT
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Tire B · Dunlop Grandtrek AT20
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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.

74

Leads

Discoverer AT3 LT

Amazon