tirewheelguide
Head-to-head Updated

Dunlop Grandtrek AT20 vs Cooper Discoverer AT3 4S — Compared

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

Discoverer AT3 4S is ahead, 76–46

Check price on Amazon · Discoverer AT3 4S or Grandtrek AT20 on Amazon
Add your size for an exact match
/R

Both Amazon links then search this exact size.

TireWheelGuide may earn a commission from purchases made through these links.

Tire BCooper

Discoverer AT3 4S

All Season

Tests – · 1 test Owners 81 · 688 reviews

“Suggestions for replacing AT tires on SUV I have an expedition, and used to need AT tires because of where I used to live and work, but now find I don't need them. I was running some Cooper Discoverer AT3 4S. Absolutely fantastic tires, but now I want to get some all weather since its mostly suburban and highway driving. We get a lot of snow so that's important to me as well. Any suggestions or real world advice? Thanks!”

Category by category

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

  1. 43

    Dry

    Discoverer AT3 4S +35
    78
    Why this score
    SourceGrandtrek AT20Discoverer AT3 4S
    Reviews found online2984
  2. 42

    Wet

    Discoverer AT3 4S +40
    82
    Why this score
    SourceGrandtrek AT20Discoverer AT3 4S
    Reviews found online3386
  3. 49

    Snow

    Discoverer AT3 4S +23
    72
    Why this score
    SourceGrandtrek AT20Discoverer AT3 4S
    Reviews found online3674
  4. 51

    Comfort

    Discoverer AT3 4S +25
    76
    Why this score
    SourceGrandtrek AT20Discoverer AT3 4S
    Reviews found online3483
  5. 57

    Noise

    Discoverer AT3 4S +15
    72
    Why this score
    SourceGrandtrek AT20Discoverer AT3 4S
    Reviews found online4281
  6. 52

    Treadwear

    Discoverer AT3 4S +21
    73
    Why this score
    SourceGrandtrek AT20Discoverer AT3 4S
    Professional tests (TWG score)–71
    Reviews found online4277
  7. 34

    Handling

    Discoverer AT3 4S +43
    77
    Why this score
    SourceGrandtrek AT20Discoverer AT3 4S
    Reviews found online3477
Scores at a glance
CategoryDunlop Grandtrek AT20Cooper Discoverer AT3 4S
Relative Score 46 76
Dry 43 78
Wet 42 82
Snow 49 72
Comfort 51 76
Noise 57 72
Treadwear 52 73
Handling 34 77

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.

Important
NoneLessNeutralMoreMost
Important
NoneLessNeutralMoreMost
Neutral
NoneLessNeutralMoreMost
Less important
NoneLessNeutralMoreMost
Less important
NoneLessNeutralMoreMost
Important
NoneLessNeutralMoreMost
Neutral
NoneLessNeutralMoreMost
Recomputed
Headline score

Grandtrek AT20

Discoverer AT3 4S

Pros, cons & observations

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

Tire A 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

Tire B Discoverer AT3 4S

Pros

  • Exceptionally quiet and smooth on-road ride compared to typical all-terrain tires
  • Superb traction in wet, rainy, and deep winter snow conditions
  • Strong value and competitive pricing relative to performance and lifespan

Cons

  • Potential for accelerated tread wear under heavy off-road use or demanding mountain driving
  • Occasional reports of balancing issues or out-of-round tires requiring multiple adjustments
  • Minor fuel economy drop or increased rolling resistance when switching from standard highway tires
All owner themes in the Discoverer AT3 4S review

What real owners are saying

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

Tire A

Dunlop Grandtrek AT20

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

Tire B

Cooper Discoverer AT3 4S

Positive

Community sentiment for the Cooper Discoverer AT3 4S is predominantly positive, with drivers praising its quiet highway ride, strong traction across snow, rain, and dry pavement, and appealing appearance. Several owners note that while it handles light off-road duties and daily driving well, tread life occasionally falls short of mileage expectations. In addition, multiple posts highlight frustration and concern regarding availability and recent discontinuation across various sizes.

r/HondaElement ·74 upvotes ·2021-02-15

“Got some 225/75/16 Cooper Discoverer AT3 4s - Great fit on stock setup.”
r/4x4 ·12 upvotes ·2026-07-08

“They Discontinued My Tire! I've been using Cooper Discoverer AT3 4s forever. For some reason Cooper, in it's infinite wisdom, has discontinued the 265 75r 16 size so I need a replacment. I'm in Southern California and do quite a bit of wildlife habitat restoration work in dry desert conditions. This involves lots and lots of highway miles as well as dirt roads from good to, on what planet is this a road. Occasionally we are even driving up dry washes, trying to avoid all the nasty sidewall eating rocks and spiny bushes. The tread on the discoverer is pretty modest and quite on the highway but when aired downed, runs well in sandy conditions. They even work pretty well in rocky conditions. The other thing is they wear really well. Ive got 60k+ miles on my current set and can squeeze another 10k out of them if I have to. So to the point, Im looking for suggestions for a replacment. Any help would be greatly appreciated.”
bobistheoilguy.com ·2019-06-26

“I ran a set of Cooper Discoverer AT3's over 72k miles and never had an issue. loved them. now i have a set of Cooper Discoverer AT3 4S's and they are even better in traction and ride.”
Top themes
#Snow and wet traction#Quiet highway ride#Tread life and longevity#Discontinuation and availability#Comfortable ride quality#Mild off-road performance

Based on 27 community posts

Specs side by side

Attribute A · Dunlop Grandtrek AT20 B · Cooper Discoverer AT3 4S
CategoryAll SeasonAll Season
Vehicle typeSUV and 4x4SUV and 4x4
Sizes available914
Rim diameters15″ – 18″15″ – 22″
Tread depth—12 - 14/32″
UTQG—620 A B
Treadwear warranty—65,000 mi
SidewallBlackwallBlack Side Wall - Raised Outline White Lettering
Max pressure—44 - 50 psi

Which one should you actually buy?

Dunlop Grandtrek AT20

Cooper Discoverer AT3 4S

Winner: Cooper Discoverer AT3 4S — 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 4S scores 77 vs 34 on handling.

Pick tire B Your priority is wet-weather safety

Cooper Discoverer AT3 4S scores 82 vs 42 on wet.

Pick tire B You want the most grip on dry roads

Cooper Discoverer AT3 4S scores 78 vs 43 on dry.

Pick tire B You want the most comfortable ride

Cooper Discoverer AT3 4S scores 76 vs 51 on comfort.

Tire A · Dunlop Grandtrek AT20
Check price on Amazon
Tire B · Cooper Discoverer AT3 4S
Check price on Amazon

TireWheelGuide may earn a commission from purchases made through these links.

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 4S

Amazon