Many tyres, regardless of whether they are summer tyres or winter tyres, can have symmetric or asymmetric tread patterns. Drivers often wonder what different characteristics these tyre tread patterns offer.
Asymmetric tread patterns are seen very frequently on today’s car tyres. Symmetric treads also exist, but these are less technologically advanced and, consequently, have started to appear less and less. Symmetric designs can currently be found on smaller, compact city cars, as well as trucks and delivery vehicles.
Asymmetric tyres stand out due to having larger blocks on the outer side, ensuring a better grip on corners and when driving on dry surfaces. The inner part of the tyre is, in turn, responsible for good handling in wet weather. Because of this, asymmetric tyres are commonly fitted to vehicles with more powerful engines, which are typically driven at higher speeds.
Advantages of asymmetric tyres
Every tyre designer has different priorities, changing the attributes and strengths of a given type of tyre. As such, there is no such thing as an ideal tyre, although asymmetric designs do offer a number of advantages. The most common benefits of these modern tyres include:
- Advanced production technologies.
- A design based on computer simulations.
- Due to the optimised patterns of tread blocks, asymmetric tyres wear down slower.
- Noise levels are reduced, without worsening the resistance to aquaplaning or overall driving quality.
- Asymmetric tyres are often somewhat less noisy than directional treads.
Disadvantages of asymmetric tyres
Of course, no tyre is ever perfect. Although they are much better than symmetric tyres, there are a few drawbacks to using asymmetric tyres. These include:
- A higher price.
- On four-wheel-drive vehicles a diagonal rotation of tyres is recommended every 6,200 to 9,300 miles. It’s more complex, as the tyres need to be switched between rims.
How to fit asymmetric tyres
Due to their pattern, asymmetric tyres require a specific method of fitting. Keep reading to find out how to fit asymmetric car tyres, with a step by step guide.
Scroll down to see all the steps required to fit an asymmetric tyre to a car wheel. Alongside these photographs, we have provided key instructions and important rules to ensure a correct fitting for your vehicle.
What are the key characteristics of asymmetric tyres?
Asymmetric tyres have different tread patterns on the left and right sides. The outside (the left-hand side of the tread in the case of the photograph below) is responsible for tyre’s performance on dry surfaces, with elements intended to ensure stability on corners. The inside part of the tyre (the right-hand side on the image below) is intended to expel water rapidly, protecting you against aquaplaning, while also being responsible for the tyre’s general behaviour in wet conditions.
How to recognise a tyre with an asymmetric tread
- An asymmetric tread has differently shaped sides - the outer part will noticeably differ from the inner part.
- Because of this, asymmetric tyres are marked “OUTSIDE” and “INSIDE”. When the tyre is correctly fitted, the “OUTSIDE” mark should be visible.
- It is also worth noting that the “INSIDE” mark will only be visible on the vehicle when standing underneath in a pit.
What are the dangers of driving on asymmetric tyres the wrong way around?
If your asymmetric tyres are fitted the wrong way around, you will likely not feel any changes in traction or precision of handling, as long as you are on a dry surface. Even then, you will still notice an increased noise level.
In wet weather, on the other hand, there will be numerous changes. This includes a noticeable reduction in speed, an increased chance of aquaplaning and, during fast cornering, a sudden loss of grip.
Remember to check what the tyre fitter has done every time your wheels are placed on your vehicle. An incorrect fitting of asymmetric tyres - with the axis of rotation opposite to that intended by the manufacturer - remains one of the most commonly occurring errors.
These structural differences mean that asymmetric tyres must be fitted in a certain direction, in accordance with the markings that appear on both sides of the tyre.
In short, the side of the tyre that needs to face the inside of the vehicle is marked “INSIDE”, while the side marked “OUTSIDE” must be visible to someone standing next to the vehicle when the wheel and tyre have been mounted. When it comes to the external side, however, there may be an alternative label, such as “SIDE FACING OUTWARDS” or “MOUNT THIS OUTSIDE”, but it should nonetheless be clear which side is which.
The INSIDE marking on an asymmetric tyre should appear on the inner side of the wheel.
The OUTSIDE marking on an asymmetric tyre must be on the same side as the front of the wheel.
Asymmetric tyres were formerly used on high-performance cars, but they can now be also found on popular mid-range vehicles. This is because of their unique advantages.
Specifically, these tyres combine the parameters of both symmetric tyres and directional tyres. This allows smooth cornering, even when driving fast. They are also a great choice for cars with modern braking and traction support systems, as they interact very well with these features.
Fitting an asymmetric tyre
Even when your tyres are fitted at a prestigious and highly renowned service centre, using the very best equipment, it is always useful to keep an eye on what is being done with your tyres. Just like anyone else, a tyre fitter can make mistakes and these are easier to spot when someone is watching from the outside.
This is important, because incorrectly fitted tyres can cause numerous problems, as they are designed to provide specific benefits at specific sides and angles of the tyre. If they are the wrong way around, the “INSIDE” side - designed to help with corners - will be on the outside, where it has little influence on cornering.
Before you start fitting your tyre, the valve must first be unscrewed:
The rim is then placed on a special mounting machine. This device is essential when fitting a tyre onto a wheel:
Before fitting the tyre, it should be cleaned with a special brush for this purpose, which should remove any remnants of the lubricant used during the last fitting:
Before the tyre is mounted, the edges are covered with a special tyre mounting paste which helps apply the tyre quickly to the rim and further protects against loss of pressure:
The correct process for fitting a tyre on a wheel, using specialised equipment and fitting machinery:
When fitting an asymmetric tyre, make sure that the “OUTSIDE” marking is on the same side as the front of the wheel:
Once the tyre has been fitted, it can then be pumped up:
If you have completed these steps, your tyre should be ready to go!
The history of asymmetric tyres
The first mass-produced asymmetric tyre was the Michelin X-AS, which launched in 1964. It offered a combination of positive features that had previously been hard to find on a single tyre, combining a good resistance to aquaplaning and an excellent precision of handling.
The inside of the tread provided the required rigidness to ensure precise handling on corners, while the outside was responsible for expelling water.
The X-AS tyre was capable of travelling safely at speeds of up to 130 mph. It provided superb stability on straight roads, as well as on turns, and unprecedented levels of grip in all weather conditions. The tyre advertisements at the time illustrated the perfection of the human foot, which is also asymmetric, comparing a foot to the tyre’s ideal performance parameters.
Overall, the X-As model was highly regarded by manufacturers of renowned makes of vehicle. It was factory fitted on the following cars:
- Bentley S3 and T,
- Alpine A-110,
- Alfa Romeo GTV 1750/2000
- BMW 2002 Ti/Tii,
- Fiat 124 Coupe/Spider,
- Datsun Fairlady and 240 Z,
- Citroen DS 21 Pallas,
- Ford Capri and Lotus-Cortina,
- Mercedes W100 (600) and W113 (230/250/280 SL),
- Lotus Elan,
- Peugeot 404 Injection,
- Triumph TR4A-IRS,
- TR5 and TR6,
- Rolls-Royce Silver Shadow,
- Porsche 911/912.
The Michelin X-AS remained as a popular standard on the market from its inception through to the late 1970s.
In the second half of the 1960s, the Uniroyal tyre company promoted the Master series, which featured different tread patterns for front and rear tyres. The company designed the model for popular makes of cars. It was argued that the tyres on the front and rear axles performed different roles.
While the tyres at the front were responsible for turning, expelling water and braking, the rear models served chiefly for driving (the classical drive system was still dominant at that time) and were jointly responsible for the vehicle’s stability and balance. For this reason, the rear tyres were made slightly wider than the front ones. These differentiated tyres failed to capture the market, as they were twice as expensive as conventional tyres.
The best asymmetric tyres
Just as with any other tyres, asymmetric tyres can vary in quality, so it helps to invest in a set of high quality models. You should also consider using asymmetric summer tyres and asymmetric winter tyres.
Among the asymmetric tyres available for summer we recommend the following models:
The best asymmetric tyres for winter:
Of course, which tyre is best for you depends on your individual preferences, driving style and road conditions, as well as which criteria are the most important to you. However, asymmetric tyres certainly offer a number of benefits, so knowing which option is more suitable for you will certainly help you make the best choice.