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Head-to-head Updated

Cooper Discoverer STT PRO vs Yokohama Geolandar G91A — Compared

Relative Score (0–100): the weighted average of the categories below, each 60% road tests and 40% owner reviews (comfort 40/60). Based on 0 + 0 road tests and 422 + 5 owner reviews. How we score

Discoverer STT PRO is ahead, 64–39

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Yokohama Geolandar G91A
Tire BYokohama

Geolandar G91A

All-Season tire

± 8Provisional

Tests – · none yet Owners 24 · 5 reviews

Category by category

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

  1. 64

    Dry

    Discoverer STT PRO +26
    38
    Why this score
    SourceDiscoverer STT PROGeolandar G91A
    Professional tests (TWG score)≈ 66 (est.)≈ 49 (est.)
    Reviews found online6322

    Discoverer STT PRO: 60% × 65.7 (est.) + 40% × 62.5 = 64

    Geolandar G91A: 60% × 48.7 (est.) + 40% × 21.6 = 38

    No road tests of dry for Discoverer STT PRO. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.42).

    No road tests of dry for Geolandar G91A. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.42).

  2. 68

    Wet

    Discoverer STT PRO +35
    33
    Why this score
    SourceDiscoverer STT PROGeolandar G91A
    Professional tests (TWG score)≈ 68 (est.)≈ 43 (est.)
    Reviews found online6620

    Discoverer STT PRO: 60% × 68.4 (est.) + 40% × 66.4 = 68

    Geolandar G91A: 60% × 42.7 (est.) + 40% × 19.6 = 33

    No road tests of wet for Discoverer STT PRO. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.55).

    No road tests of wet for Geolandar G91A. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.55).

  3. 67

    Snow

    Discoverer STT PRO +18
    49
    Why this score
    SourceDiscoverer STT PROGeolandar G91A
    Professional tests (TWG score)≈ 69 (est.)≈ 59 (est.)
    Reviews found online6533

    Discoverer STT PRO: 60% × 68.7 (est.) + 40% × 64.6 = 67

    Geolandar G91A: 60% × 58.8 (est.) + 40% × 33.4 = 49

    No road tests of snow for Discoverer STT PRO. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.32).

    No road tests of snow for Geolandar G91A. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.32).

  4. 54

    Comfort

    Discoverer STT PRO +22
    32
    Why this score
    SourceDiscoverer STT PROGeolandar G91A
    Professional tests (TWG score)≈ 64 (est.)≈ 58 (est.)
    Reviews found online4714

    Discoverer STT PRO: 40% × 64.4 (est.) + 60% × 47.4 = 54

    Geolandar G91A: 40% × 57.7 (est.) + 60% × 14.3 = 32

    No road tests of comfort for Discoverer STT PRO. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.20).

    No road tests of comfort for Geolandar G91A. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.20).

  5. 53

    Noise

    Level
    53
    Why this score
    SourceDiscoverer STT PROGeolandar G91A
    Professional tests (TWG score)≈ 66 (est.)≈ 66 (est.)
    Reviews found online3233

    Discoverer STT PRO: 60% × 66.3 (est.) + 40% × 31.8 = 53

    Geolandar G91A: 60% × 66.3 (est.) + 40% × 32.8 = 53

    No road tests of noise for Discoverer STT PRO or Geolandar G91A. The test half is the tested tires’ average (66): owners’ noise ratings barely follow the road tests.

  6. 62

    Treadwear

    Discoverer STT PRO +22
    40
    Why this score
    SourceDiscoverer STT PROGeolandar G91A
    Professional tests (TWG score)≈ 64 (est.)≈ 51 (est.)
    Reviews found online6024

    Discoverer STT PRO: 60% × 64.1 (est.) + 40% × 59.7 = 62

    Geolandar G91A: 60% × 51.2 (est.) + 40% × 23.7 = 40

    No road tests of treadwear for Discoverer STT PRO. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.36).

    No road tests of treadwear for Geolandar G91A. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.36).

  7. 52

    Handling (owners)

    No comparison
    –
    Why this score
    SourceDiscoverer STT PROGeolandar G91A
    Reviews found online52–
Scores at a glance
CategoryCooper Discoverer STT PROYokohama Geolandar G91A
Relative Score 64 39
Dry 64 38
Wet 68 33
Snow 67 49
Comfort 54 32
Noise 53 53
Treadwear 62 40
Handling (owners) 52 –

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

Weight the categories that matter to you

Wet grip starts at “Important”. Treadwear starts at “Neutral” here: road tests measured it for at most one of the two tires, so it rests on owner reviews. Move the sliders and the scores update instantly.

Important
NotLessNeutralImportantMost
Important
NotLessNeutralImportantMost
Neutral
NotLessNeutralImportantMost
Less important
NotLessNeutralImportantMost
Less important
NotLessNeutralImportantMost
Neutral
NotLessNeutralImportantMost
Less important
NotLessNeutralImportantMost

Only one of the two tires has a score here, so this weight changes nothing in the head-to-head.

Recomputed
Headline score
± 7

Discoverer STT PRO

± 8

Geolandar G91A

Only categories both tires have data for count toward the headline score.

Pros, cons & observations

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

Tire A Discoverer STT PRO

Pros

  • Outstanding off-road traction in mud, rocks, and dirt
  • Surprisingly low road noise and smooth ride for a mud-terrain tire
  • Aggressive and appealing visual design with tough sidewalls

Cons

  • Can be difficult to balance properly, leading to vibrations for some users
  • Faster tread wear reported by a subset of drivers under heavy use
  • Reduced traction in specific conditions like deep sand or packed snow/ice
All owner themes in the Discoverer STT PRO review

Tire B Geolandar G91A

Not enough owner reviews yet to extract themes.

What real owners are saying

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

Tire A

Cooper Discoverer STT PRO

Positive

Community members widely praise the Cooper Discoverer STT PRO for its exceptional off-road traction, towing capability, and dependable handling in mud, rain, and snow. While users note it balances well and rides comfortably for a mud-terrain tire, the most common criticisms involve pavement road noise that increases with wear and concerns regarding tread life on heavy trucks.

duramaxforum.com ·2015-09-14

“Installed the stt pro's on the 10 duramax , so far I really like the tires . Put them to the test backcountry camping (towing 5th wheel) & they were good in the mud & towing. They arent the quietest tires , but did quiet down after some miles. Comparable in noise to the trail grapplers or slightly louder, they weren't squirmy when new, unlike the trailer grapplers I had on my old dodge diesel for the 1st few hundred miles Sent from AutoGuide.com Free App”
powerstroke.org ·2022-04-14

“I have used Cooper Discoverer STT Pro's in mud, rain, snow, ice, sand, etc. They have performed just fine in each. They are a bit louder on the highway, but it's not that noticable. -jokester”
r/XTerra ·99 upvotes ·2023-03-31

“New shoes. Cooper Discoverer STT Pro. 285/75/16”
Top themes
#off-road traction#highway road noise#mud and snow performance#tread wear life#heavy truck towing#balancing and ride quality

Based on 38 community posts

Tire B

Yokohama Geolandar G91A

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

Specs side by side

Attribute A · Cooper Discoverer STT PRO B · Yokohama Geolandar G91A
CategoryMud-Terrain tireAll-Season tire
Vehicle typeSUV and 4x4SUV and 4x4
Sizes available231
Rim diameters16″ – 20″17″
Tread depth18 - 22/32″10/32″
UTQG—280 B A
SidewallBlack Side Wall - Raised White LetteringBlackwall
Max pressure35 - 80 psi44 psi

Which one should you actually buy?

Cooper Discoverer STT PRO

Yokohama Geolandar G91A

Winner: Cooper Discoverer STT PRO — better wet, dry and comfort. It leads or ties in every category we score. Yokohama Geolandar G91A rests on little evidence so far (0 tests, 5 reviews), so read this result as provisional.

Pick tire A Your priority is wet-weather safety

Cooper Discoverer STT PRO scores 68 vs 33 on wet.

Pick tire A You want the most grip on dry roads

Cooper Discoverer STT PRO scores 64 vs 38 on dry.

Pick tire A You want the most comfortable ride

Cooper Discoverer STT PRO scores 54 vs 32 on comfort.

Pick tire A You want the longest tread life

Cooper Discoverer STT PRO scores 62 vs 40 on treadwear.

Tire A · Cooper Discoverer STT PRO
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Tire B · Yokohama Geolandar G91A
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Discoverer STT PRO or Geolandar G91A?

Which is better in the wet, Discoverer STT PRO or Geolandar G91A?

Cooper Discoverer STT PRO, 68 vs 33 on our wet score.

Which grips better on dry roads, Discoverer STT PRO or Geolandar G91A?

Cooper Discoverer STT PRO, 64 vs 38 on our dry score.

Which is better in snow, Discoverer STT PRO or Geolandar G91A?

Cooper Discoverer STT PRO, 67 vs 49 on our snow score.

Which is quieter, Discoverer STT PRO or Geolandar G91A?

Neither, by our numbers: 53 vs 53 on the noise score, within 3 points.

Which is more comfortable, Discoverer STT PRO or Geolandar G91A?

Cooper Discoverer STT PRO, 54 vs 32 on our comfort score.

Which lasts longer, Discoverer STT PRO or Geolandar G91A?

Cooper Discoverer STT PRO, 62 vs 40 on our treadwear score.

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.

Handling is the exception: road tests measure it inside the dry and wet scores, so its own row comes from owner ratings only and starts as less important.

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