While all-season tires are designed to bridge the gap between summer and winter tire capabilities, they may not offer the same level of performance as specialized tires in extreme heat. I mean, in areas with consistently high temperatures, summer tires could be a more effective choice.
The bottom line: All-season tires are versatile but not optimal in extreme temperatures. They are engineered to perform within a temperature range of 32°F (0°C) to 90°F (32°C), beyond which their efficiency starts to decline. So, they aren’t able to provide you with the same level of dry and wet traction, along with fuel economy and tread life, though interestingly, their noise reduction properties improve.
Let’s dive into how heat impacts the different performance metrics of all-season tires, starting with dry performance.
Dry Performance
Effective dry performance hinges on maximizing rubber-to-road contact, where the greater the contact, the better the performance.
That’s why wider tires tend to do better.
However, rising temperatures can significantly alter a tire’s braking and handling capabilities. So, let’s examine these changes in detail.
Dry Braking In Warmer Summer
Initially, as temperatures rise, the tread compound of all-season tires softens up slightly, improving adherence with the road, allowing for better grip on dry surfaces.
However, if the temperatures become too high, the tread compound can become overly soft. This over-softening can actually reduce the tire’s effectiveness in braking, by causing lugs to distort more.
This makes braking not so great, because the tire lugs get all mushy and squish into each other instead of gripping the road. It’s like they’re having a little squabble and forget to do their job.
And this process creates further heat, creating a vicious cycle of increasing softness and decreasing effectiveness.
In simple terms, when all-season tires get too squishy, they start soaking up some of the brake energy, like a sponge, instead of passing it straight onto the road. Imagine pressing your hand into a really soft pillow. The pillow squishes and absorbs the push, rather than moving forward.
So, it makes sense why, with heat, AS tires show longer braking distances in tests.
Side Note: Though you can improve dry performance of all-season tires, with these aspects: https://tiredriver.com/improving-dry-performance-all-season-tires/
Dry Handling With Heat
Handling is a combination of lateral grip, but here steering response is a larger performance contributor. And with greater temperature, both of these aspects get significantly affected on all-season tires.
Now, lateral grip gets affected in a similar manner, as I explained above.
As for steering, the impact arises from the following dynamics:
Now, as the tire corners, most of the weight on it gets concentrated on the shoulders. And with more heat, those lugs become more bendy.
And with lugs bending more, they take/waste time in getting back into shape. And that time is reflected in the delay you get between steering inputs and outputs.
Summer’s Heat Affect on Wear and Fuel Economy
All-season tires typically have a tread compound that is designed to balance grip in wet and dry conditions, as well as durability. So, with right temperatures, usually around 60°F, these tires offer better tread longevity compared to winter and summer tires.
But that’s not the case in harsher climates. Let me explain why.
In hot climates, all-season tires struggle to dissipate heat as efficiently as summer tires, resulting in increased pliability. This excess flexibility can cause the tire treads to bend more, increasing rolling resistance and reducing both tread life and fuel efficiency.
Learn more about it here: Do All-Season Tires Use More Fuel?
Though there are some all season tires, mostly in the standard touring category, that are harder and provide decent tread life.
For Your Info: Out of all these standard touring tires, the Michelin Defender 2 provides the best tread longevity.
Summer Wet Performance
When it comes to handling wet roads, it’s all about how well a tire can kick water out from under it. This keeps the tire from skating on top of the water (that’s hydroplaning) and helps it grip the road better.
Now, all-season tires tackle this with their grooves and sipes. The grooves are like little channels that quickly push water out from under the tire.
But, even after most of the water’s gone, there’s still this really thin, super slippery layer left. That’s where sipes come in.
As the tire squishes against the road, these tiny slits open up, creating a little low-pressure zone that sucks up this last bit of water. It’s like the tire’s giving the road a quick hug, ensuring better contact.
All-season tires, with their bunch of sipes and grooves, usually do a decent job in the rain. But, they’re really affected by temperature changes.
As it gets warmer, especially over 40°F, they start to soften up. This affects their sipes and grooves. The sipes, being too soft, can’t suck up water as effectively. And the grooves? They struggle to push water out efficiently.
Basically, grooves aren’t able to create a good enough pressure differential, so they aren’t able to throw water from the middle towards the shoulders (and out of the tire).
That’s where summer tires steal the show. They’ve got a stickier rubber mix that works wonders, even with fewer grooves and sipes. They just grip onto the road better and fight off hydroplaning like a champ.
Think of summer tires like this: their super grippy compound not only holds onto the road but sometimes even leaves a bit of itself behind, kind of like leaving footprints on a sandy beach.
For Your Info: To get in to more details on how all-season tires perform in wet conditions, check this out: https://tiredriver.com/are-all-season-tires-good-in-rain/
Overall Ride Comfort With Heat
In hot conditions, all-season tires can become softer than they are designed to be. This increased softness can lead to a smoother ride since softer tires can better absorb road irregularities.
However, it’s important to note that excessively soft tires might not always be ideal. They can potentially lead to less responsive handling and a feeling of less stability, especially at higher speeds or during maneuvers.
Moving towards noise, it’s a bit complex. To understand it, you should first know the main sources of noise.
One is coming with road to rubber interaction. Then there’s air pumping in and out of grooves. Then there’s cavity noise; the list goes on and on.
Now, in general, all-season tires getting softer can lead to reduced road noise because they can absorb vibrations better. This can make the ride quieter, especially on rough or uneven surfaces.
Though tires with greater siping, becoming too soft, and deformed do tend to generate more noise in the form of growling, that mostly comes from rubber-to-road interaction and friction.
Though this depends on which category of all-season tires the tire belongs to.
For example, grand touring tires provide the most comfort, while standard touring tires are the quietest.
Anyways I want you to go deeper on all-season tires’ comfort and noise performance, you should check out: https://tiredriver.com/are-all-season-tires-comfortable-and-quiet-enough/
To Sum Things Up
In conclusion, all-season tires offer a versatile solution for varying weather conditions, but they may not be optimal in extreme temperatures, particularly high heat.
Their performance in terms of dry braking, handling, and wet road grip can be significantly affected as temperatures rise.
While they do provide a smoother ride due to increased softness in hot conditions, this can also lead to decreased responsiveness and stability.
Additionally, the effect of heat on the tire’s tread can increase rolling resistance, negatively impacting both tread life and fuel efficiency.
Therefore, while all-season tires are a practical choice for moderate conditions, in areas with consistently high temperatures, specialized summer tires might be a more effective option.
