Tests – · none yet Owners 60 · 5 reviews
Kumho Solus Vier KH21 looks discontinued: no new owner reviews or road tests in five years and no current EU tyre label.
Head-to-head
Updated
Kumho Solus Vier KH21 vs Michelin Pilot Sport 4 S — Compared
Relative Score (0–100): the weighted average of the categories below, each 60% road tests and 40% owner reviews. Based on 0 + 27 road tests and 5 + 6,614 owner reviews. How we score
Pilot Sport 4 S is ahead, 84–65
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Tests 81 · 27 tests Owners 82 · 6,614 reviews
Best test result: #1 of 15 in 2021 Auto Bild 19 inch Summer Tyre Test (dry braking)
“A note about the pilot sport 4 S: in cold weather (below 5 degrees) even if it isn't icy, the tyre compound hardens and has dramatically reduced grip. They are excellent summer tyres though, good in the wet too. These days I run Uniroyal rainsport 5 and they're very good.”
Category by category
Relative Score per category, 0–100. Open “Why this score” for the tests and owner ratings behind it.
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66
Dry
Pilot Sport 4 S +2692Why this score
Source Solus Vier KH21 Pilot Sport 4 S Professional tests (TWG score) · – / 25 tests ≈ 66 (est.) 94 Reviews found online 65 89 Solus Vier KH21: 60% × 66.5 (est.) + 40% × 64.6 = 66
Pilot Sport 4 S: 60% × 93.6 + 40% × 88.6 = 92
No road tests of dry for Solus Vier KH21. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.40).
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71
Wet
Pilot Sport 4 S +1485Why this score
Source Solus Vier KH21 Pilot Sport 4 S Professional tests (TWG score) · – / 26 tests ≈ 70 (est.) 85 Reviews found online 71 85 Solus Vier KH21: 60% × 70.4 (est.) + 40% × 70.9 = 71
Pilot Sport 4 S: 60% × 85.3 + 40% × 84.6 = 85
No road tests of wet for Solus Vier KH21. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.56).
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62
Comfort
Pilot Sport 4 S +1375Why this score
Source Solus Vier KH21 Pilot Sport 4 S Professional tests (TWG score) · – / 6 tests ≈ 67 (est.) 70 Reviews found online 54 81 Solus Vier KH21: 60% × 66.5 (est.) + 40% × 54.1 = 62
Pilot Sport 4 S: 60% × 70.4 + 40% × 80.8 = 75
No road tests of comfort for Solus Vier KH21. The test half is the tested tires’ average (69): owners’ comfort ratings barely follow the road tests.
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–
Noise
No comparison69Why this score
Source Solus Vier KH21 Pilot Sport 4 S Professional tests (TWG score) · – / 20 tests – 70 Reviews found online – ≈ 67 (est.) Pilot Sport 4 S: 60% × 70.3 + 40% × 67.3 (est.) = 69
No owner ratings of noise for Pilot Sport 4 S. The owner half is the owners’ average (67): owners’ noise ratings barely follow the road tests, so the tests say nothing about how owners would rate it.
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55
Treadwear
Pilot Sport 4 S +1671Why this score
Source Solus Vier KH21 Pilot Sport 4 S Professional tests (TWG score) · – / 1 tests ≈ 60 (est.) 70 Reviews found online 47 71 Solus Vier KH21: 60% × 59.8 (est.) + 40% × 46.6 = 55
Pilot Sport 4 S: 60% × 70.2 + 40% × 71.4 = 71
No road tests of treadwear for Solus Vier KH21. The test half is estimated from the owner ratings, as far as owners and testers agree (correlation 0.31).
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65
Handling (owners)
Pilot Sport 4 S +2186Why this score
Source Solus Vier KH21 Pilot Sport 4 S Reviews found online 65 86
Scores at a glance
| Category | Kumho Solus Vier KH21 | Michelin Pilot Sport 4 S |
|---|---|---|
| Relative Score | 65 | 84 |
| Dry | 66 | 92 |
| Wet | 71 | 85 |
| Comfort | 62 | 75 |
| Noise | – | 69 |
| Treadwear | 55 | 71 |
| Handling (owners) | 65 | 86 |
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
Less important
NotLessNeutralImportantMost
Less important
NotLessNeutralImportantMost
Only one of the two tires has a score here, so this weight changes nothing in the head-to-head.
Neutral
NotLessNeutralImportantMost
Less important
NotLessNeutralImportantMost
Recomputed
Headline score
65
/ 100
Solus Vier KH21
84
/ 100
Pilot Sport 4 S
Only categories both tires have data for count toward the headline score.
The professional test results behind the scores
Per discipline: the average % of the best tire over every test both tires were in, and how many of those tests each one won. “Different tests” rows compare results from separate tests.
| Discipline | Category | Solus Vier KH21 | Pilot Sport 4 S | Δ | Head-to-head |
|---|---|---|---|---|---|
| Also published by the testers (not in the score) | |||||
| Overall Ranking | Overall | #9/9 2011 Auto Express Winter Tyre Test | #1/10 2026 ACE Summer Tyre Test | – | Different tests |
Pros, cons & observations
Themes extracted from owner reviews found online — not the opinion of TireWheelGuide.
Tire A Solus Vier KH21
Pros
- Cost-effective pricing compared to premium alternatives
- Certified for winter use with the mountain and snowflake symbol
- Reliable grip and handling characteristics when tires are new
Cons
- Rapid and uneven tread wear, particularly on front axles
- Increased road noise and reduced comfort as the rubber compound hardens over time
- Susceptibility to balancing issues and structural deformation
Tire B Pilot Sport 4 S
Pros
- Exceptional grip and predictable handling in both dry and wet conditions
- Noticeable reduction in road noise and improved ride comfort compared to competitors and run-flats
- Sharper steering response and improved cornering stability
Cons
- High initial purchase price
- Rapid tread wear reported by some aggressive drivers and track users
- Soft sidewalls can cause a slightly vague or laggy initial response during rapid steering transitions
What real owners are saying
From Reddit, forums and review threads. Not part of our score
Tire A
Kumho Solus Vier KH21
We haven't collected enough community discussion about this tire yet.
Tire B
Positive
Michelin Pilot Sport 4 S
The community widely regards the Michelin Pilot Sport 4 S as a benchmark max-performance summer tire, praising its outstanding dry and wet grip, stability, and daily driving refinement. Common criticisms focus on its premium price, rapid tread wear on high-powered heavy vehicles or hot track sessions, and significantly reduced grip in cold weather. Many enthusiasts consider it an ideal street tire, though some note softer sidewalls compared to predecessors or recommend dedicated track tires for hard circuit driving.
rennlist.com
“Quote: Originally Posted by gcurnew I got the Goodyear F1s on my car when delivered and found them surprisingly nice: good grip, quiet, compliant ride. Put PS4Ss on last year and while I'm happy with them, they are a tad noisier than the F1s with a slightly stiffer ride and no apparent difference in grip or handling. I know the Michelins are the "go to" tire and pretty much everyone raves about them...but I'm in the camp that thinks the F1s are an equivalent tire. Having had both, I would have just bought a set of F1 rears (my fronts were only partially worn) rather than a full set of Michelins. I've used Michelin exclusively for the past two decades. My car came with the F1s and was pleasantly surprised. Dare I say better than 4S? Excellent in the wet and dry and they don't seem to get greasy like the 4Ss can when pushed. Still don't know how they wear but unless performance drops off or noise suddenly goes up like with Pirellis, I might buy them again.”
camaro6.com
“Quote: Originally Posted by D_H I hated the Michelin Pilot Sport 4 S tires. Was not happy with the wear. I wanted a drivable tire, and that's why I got them. They were pricy. Didn't last anywhere near the 30,000 mile range. Lasted just over 15,000 miles. Tire wear was not even, and the performance is a joke. But again, that's not why I got them. Tires always want to slip traction. I'm just going to stick with the stock tires from now on. I was wanting to know what everyone thought about these Atturo AZ850 front and rear tires though. I just put a very lightly used (from a friend) set of Atturo AZ850's in 1LE size on my 2020 2SS (I mounted them on MRR017 1LE Replica Wheels (285/30ZR20 Fronts and 305/30ZR20 Rears)), so far VERY happy with them especially considering the cost... They definitely hook better than my old 275 run flats...”
r/cars
·4 upvotes ·2018-08-21
“I’ll say this. Going from the Pilot Super Sport to the Pilot Sport 4 S of the same size, I’m disappointed in the soft sidewall of the 4 S. This is an 8.5” wide wheel with 235/40/18 tires. The left-right fast slalom action got a bit mushy like the weight transfer was slowed down when I switched to the 4 S. I think a shorter sidewall 4 S would perform better in this way, or the same tire on a 9” wide wheel too. That said, the dry and wet grip is exceptional. To save money, I’d recommend the Continental ExtremeContact Sport.”
Top themes
#Wet and dry grip#Track day durability#High price vs alternatives#Tread life and wear#Cold weather performance#Sidewall stiffness and comfort
Based on 208 community posts
Specs side by side
| Attribute | A · Kumho Solus Vier KH21 | B · Michelin Pilot Sport 4 S |
|---|---|---|
| Category | All Season | Summer |
| Vehicle type | Passenger Car / Crossover | Passenger Car / Crossover |
| Sizes available | — | 110 |
| Rim diameters | — | 17″ – 22″ |
Which one should you actually buy?
65
/ 100
Kumho Solus Vier KH21
84
/ 100
Michelin Pilot Sport 4 S
Winner: Michelin Pilot Sport 4 S — better dry, handling and treadwear. It leads or ties in every category we score. Kumho Solus Vier KH21 rests on little evidence so far (0 tests, 5 reviews), so read this result as provisional.
Pick tire B
You want the most grip on dry roads
Michelin Pilot Sport 4 S scores 92 vs 66 on dry.
Pick tire B
You enjoy sharp, responsive handling
Michelin Pilot Sport 4 S scores 86 vs 65 on handling.
Pick tire B
You want the longest tread life
Michelin Pilot Sport 4 S scores 71 vs 55 on treadwear.
Pick tire B
Your priority is wet-weather safety
Michelin Pilot Sport 4 S scores 85 vs 71 on wet.
Tire A · Kumho Solus Vier KH21
Tire B · Michelin Pilot Sport 4 S
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Solus Vier KH21 or Pilot Sport 4 S?
Which is better in the wet, Solus Vier KH21 or Pilot Sport 4 S?
Michelin Pilot Sport 4 S, 85 vs 71 on our wet score.
Which grips better on dry roads, Solus Vier KH21 or Pilot Sport 4 S?
Michelin Pilot Sport 4 S, 92 vs 66 on our dry score.
Which is more comfortable, Solus Vier KH21 or Pilot Sport 4 S?
Michelin Pilot Sport 4 S, 75 vs 62 on our comfort score.
Which lasts longer, Solus Vier KH21 or Pilot Sport 4 S?
Michelin Pilot Sport 4 S, 71 vs 55 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