The Korean Kumho Ecsta PA51 is a great pick, where it shows strengths in noise reduction and tread life but requires improvements in wet and snow performance, as well as directional grip in dry conditions. Let’s check this tire out in greater details.
Key Takeaway
Overall, the Kumho Ecsta PA51 excels in:
- Noise comfort. It’s the quietest tire in UHP all-season category.
- Overall dry handling, with responsive steering and good lateral grip.
- Tread longevity, often surpassing its 45k miles warranty due to its durable rubber composition.
Though the tire needs improvements in:
- Directional grip, as the tire lacks when it comes to braking.
- Wet performance, including traction and steering responsiveness.
- Winter traction, lacking in effective grip on snowy and icy surfaces.
- Road smoothness, needing a more cushioned response to uneven road surfaces.
Tread Structure
To best appreciate the tire’s performance, let’s begin with a detailed exploration of its tread design.
So, the design of the Kumho Ecsta PA51 includes an asymmetric tread pattern, easily identified by its five unique ribs or block columns.
Focusing on the outer shoulder ribs, each side displays a distinct design.
On one side, the lugs are more simplistic, characterized by straightforward linear sipes. In contrast, the other side is designed with wave-like sipes, interconnected by longitudinal slits.
Despite their differences, both sides have lateral voids and ridges connecting all blocks, which enhances the tire’s steering response.
Moving towards middle, the 3 ribs making 4 circumferential grooves, vary a lot from one another.
I mean, if you consider the central most rib, you’d note the distinct combination of notches and linear sipes.
And adjacent to this rib, one side has proper lateral voids, connecting outer circumferential grooves together, while the other side features curved notches directed towards the center.
Info on Sizes
The tire comes in 16 to inches rims. And these sizes have following specs.
- Speed ratings: V and W only.
- Load ratings: SL and XL.
- Tread depth: 10.5 and 11/32″.
- Weight: 18 to 42 lbs.
- UTQG: 500 A A.
- Treadwear warranty: 45k miles.
Internally, tire comes with 2 ply polyester, 2 steel belts, and a single nylon cap ply.
Too many all-season tires to pick from? Simplify your search – begin here.
Overall Ride Comfort
Overall ride comfort in tires is influenced by factors such as noise generation, bump absorption capabilities, and overall stability. In this context, let’s explore why the Kumho excels in these areas, particularly in noise comfort.
Noise Comfort
Road noise is largely influenced by how air interacts with the tire. As the tire rotates, air particles, especially those entering through the shoulder area, collide with the tread walls, generating noise.
Having said that, it can be explained why the Ecsta PA51 stands out as the quietest tires in my list of ultra-high performance category. See the list here: https://tiredriver.com/best-ultra-high-performance-all-season-tires/
The design of Kumho with closed up lateral voids on shoulders, (equipped with strategically placed ridges), restrict the flow of air particles into the tire, tackling with noise at the source.
Moreover, it utilizes a rubber blend that includes polymers specifically notable for their noise-absorbing qualities. These polymers are less reflective of noise waves, reducing echoing, which helps prevent in-groove resonance or noise amplification.
Moreover, the tire’s superb pitch sequencing pattern is the cherry on the top.
This pattern results in the generation of various tones, or frequencies as air particles impact the tread walls, and together those tones try to cancel out each other’s effect, further diminishing the overall noise.
Road Smoothness
Road comfort in tires is influenced by a range of elements such as the tire’s internal and external structure, tread composition, and overall design.
When considering these aspects, the Kumho Ecsta PA51 doesn’t stand out as particularly impressive, based on personal evaluations.
One of the key drawbacks of the tire is its relative hardness compared to others in its category, which results in a less comfortable experience, as it doesn’t cushion the impact from uneven road surfaces as effectively.
For Your Info: In the realm of ultra high performance all-season tires, the General G MAX 07 (review) excels in overall ride comfort. Though UHP are less comfortable compared to other tires in all-season categories.
Overall Dry Performance
Overall dry performance of a tire can be segmented in to two parts, directional grip, and overall handling. Let’s take a look at each one by one.
Directional Grip
Directional grip pertains to the tire’s capability for effective braking and acceleration. And it hinges largely on how well the rubber makes contact with the road, especially in the tire’s central region, (which bears the majority of the weight when the tire rolls in a straight line).
In this regard, the Kumho PA51 falls short. In fact its one of tire’s weakest point, as seen with my comparative testing with other tires in its ultra high performance AS segment.
I mean, compared to the Michelin Pilot All Season 4, a leading tire in terms of braking, the Ecsta PA51 showed a significant deficiency, where on average it stopped over 10 feet longer, in stopping distance tests.
Review Michelin’s tire here: https://tiredriver.com/michelin-pilot-sport-all-season-4-review/
This shortfall is largely due to the tire’s tread design, where the central ribs on its tread, are prominently voided up (laterally), limiting its overall contact patch.
Moreover, the tire’s relatively heavier weight (going up to 42 lbs), exacerbates this issue.
The increased weight adds to the overall momentum of the tire, making it more challenging to stop quickly and efficiently.
Overall Handling
The overall handling of a tire is determined by a combination of its directional grip, lateral grip, and steering response.
That’s why while the Kumho’s tire here have some limitations in directional grip, its overall dry handling is still impressive. To give you an idea, its handling lap times (on averaged tests), are similar to Bridgestone Potenza RE980+ (review), a premium ultra-high performance tire.
To understand why this is the case, it’s important to look at the three phases of cornering:
- Entering the Corner: This phase involves slowing down, possibly downshifting, and “braking” before turning.
- Mid-Cornering: This phase is when you’re at the apex of the turn, and demands accurate steering feedback.
- Exiting the Corner: This involves straightening the tires and accelerating.
Now, as already discussed in its directional grip, the Ecsta PA51 with longer braking, isn’t able to enter the corners, fast enough. Though the tire demonstrates exceptional performance in the other two critical phases here.
It delivers pretty precise and relatively swift responses to steering inputs, coupled with an excellent on-center feel. This combination results in impressive handling, as evidenced by lap test results.
For Folks who don’t know: The on-center feel of a tire is vital for maintaining control, especially after navigating a turn. It refers to the stability and feedback a driver receives when the steering wheel is in the neutral or “centered” position.
Wet Performance
When assessing a tire’s performance in wet conditions, there are three crucial factors to consider: traction, steering responsiveness, and hydroplaning resistance. Let’s explore each of these.
Aquaplaning Resistance
Hydro or aquaplaning occurs when water cannot efficiently disperse, resulting in a layer forming between the tire tread and the road surface. This layer essentially causes the tire to float, leading to a loss of control.
And here as the effectiveness of its grooves determine the overall tire’s water expulsion abilities, its central to hydroplaning resistance.
Having said that, the Kumho Ecsta PA51, although offers 4 wide enough circumferential grooves, they don’t interconnect with each other (by lateral grooves).
And this combined with the blockers within shoulder voids, impedes overall lateral evacuation of water.
Consequently, this design limitation affects the tire’s curved float speeds, though its performance in straight-line tests remains satisfactory (as its longitudinal channels still throw water out vertically).
For Your Info: Float speeds refer to the velocity at which a tire starts to float and hydroplane, often on a few millimeters deep water, To determine this precisely, I employ a telemetry system that accurately records the exact moment when the tires lose traction.
Wet Traction and Steering
In wet conditions, the functionality of a tire heavily depends on the synergy between grooves and sipes.
Now as already explained, the grooves take out majority of water and are responsible for hydroplaning resistance (predominately). While the sipes address the remaining moisture.
These sipes function by flexing to create a vacuum, drawing in water and allowing the tire’s rubber and tread elements to maintain road contact.
Having said that it can be explained why the Kumho PA51 lacks a lot when it comes to overall wet traction and steering.
The tire is hampered by a limited number of sipes, and those present are not sufficiently flexible.
I mean with these sipes, having a linear structure, they are susceptible to stiffening up, particularly when the tire takes aggressive maneuvers, reducing their effectiveness.
And yes of course, the relatively harder rubber composition of the tire exacerbates this issue, further limiting the sipes’ ability to flex.
Moreover, as the tire is less efficient at expelling water through its grooves, it places greater dependence on the sipes for overall wet traction, as less water is removed out to begin with.
That’s why in my comparative analysis, the tire lacks to even Sumitomo HTR P03 (review), which was the weakest tire in the category, before I reviewed Ecsta PA51.
Tread Longevity
The PA51 stands out for its excellent tread wear performance, particularly noteworthy in the realm of “high-performing” all-season tires.
I mean although it offers a treadwear warranty of 45k miles, it easily surpasses the 50k miles mark, given that you do all the things I mentioned here: https://tiredriver.com/how-to-increase-tread-life-on-tires/
This longevity is attributed to its rubber composition, which is specifically engineered for enhanced resistance to wear.
The tire although weighs a little, (which pushes down on lugs more as they rub against the road), it still fights off excessive wear with its denser rubber composition.
Moreover, its relatively greater tread depth is also helping here, which takes a while before it reaches down to the legal limit (in US) of 2/32″.
About its warranty: It’s important to note that the tire’s treadwear warranty is reduced to half if different sizes are used on the rear of the vehicle compared to the front.
A side note here: For those looking for a budget-friendly option in the ultra-high performance all-season tire category, the Fuzion UHP Sport AS (review) currently stands as the best choice, offering a balance of performance and value.
Snow Performance
The PA51 faces significant challenges in winter conditions, and the key factors contributing to its subpar winter performance are:
- Non-Thermally Adaptive Rubber: The tire’s material does not adapt to cold temperatures, leading to increased rigidity. This lack of flexibility prevents the tire’s ‘biters’ from effectively gripping snow and ice, particularly in harsh winter conditions.
- Limited Siping: Compared to specialized winter tires, the Kumho offers fewer sipes. This deficiency results in diminished micro-level traction, particularly needed for icy surfaces, adversely affecting its traction scores.
- Conventional Tread Design: The tire’s tread lacks the specialized notches and grooves necessary for optimal snow-to-snow contact. This deficiency compromises the tire’s grip in snowy conditions, especially in softer snow.
- Non-Scooping Lugs: With this missing features, the tire isn’t able to generate effective acceleration, as such lugs scoop snow backwards, propelling tires forward.
Consequently, with these factors combined, the Kumho Ecsta PA51 offers one of the most lacking performance on snowy terrains.
In fact it even lacks to Riken Raptor ZR A/S which is a budget pick, where in comparison, it showcased over 20 feet longer ice, and over 15 feet longer snow braking, as seen by comparative stopping distance tests.
To Conclude
In conclusion, the Kumho Ecsta PA51 showcase a mixed bag of capabilities and limitations.
Its dry performance is hindered by inadequate directional grip, particularly in braking, as it falls short compared to leading tires, (in its category of UHPAS).
However, its overall dry handling remains impressive, with responsive steering and good lateral grip.
Though the tire’s wet conditions isn’t impressive, as it comes with a limited sipe flexibility. And similarly, snow traction becomes another weak area too.
Though the tire really excels, in terms of noise comfort, where in fact it leads its category. Moreover, it also offers superb tread longevity and fuel economy as well.
