BMWs are often favored for their performance capabilities, which is why you can spot so many of them on track days. If you want to enjoy the track even with your BMW, you should make sure to choose the right tires for it.
Many drivers disregard this aspect but, in the end, the tires are the only thing that keeps you on the road. Even the best track car will drive poorly without proper tires, hence the saying “Tires win races.” This article will explain to you what types of tires are suitable for track use and what to look for when buying a set for your BMW.
Photo courtesy: Kaan.K
Tire Type
To narrow down the selection of track day tires for your BMW, you should first think about how you intend to use your car. Will you use your track day tires for driving in regular traffic as well or are you going to put on your performance tires only once you get to a track?
How often will you be racing? Thinking about your use case scenario will help you decide which type of tire you should go for. For track day use, you generally have three options – slicks, semi slicks, and performance road tires.
Slicks
The slick tires are designed strictly for racing. As their name suggests, they have a smooth surface, meaning there is no tread in the tire. While this ensures perfect handling of the car on a dry track (once warmed up to operating temperature), it also means that on the wet, you will experience aquaplaning immediately.
The tread on a regular tire is there to channel water, allowing it to escape from underneath the tire, and thus ensuring that the rubber stays in contact with the road. As the slicks are not designed to do that, they handle atrociously on a wet road or track. This is also the reason why they are illegal on regular streets.
Semi Slicks
The semi slicks are a good alternative to full-on slicks and give you a bit more versatility. They are based on the design of slick tires but do have some tread on there. While the extent of the grooves is not comparable to standard road tires, they still behave much better on the wet, compared to slicks.
The improved handling in the wet, and the overall improved versatility of the tire means that it is legal to use on the road. With that said, you should still keep in mind that semi slicks are not the ideal tire for wet roads.
A popular semi slick tire is the Michelin Cup 2, which has a really good grip while not wearing down too quickly. Drivers also often choose the Toyo Proxes R888 or R1-R, which offer great value for money.
Performance Road Tires
The performance road tires are probably your best bet if you don’t want to limit your car’s use to track only but instead, want to use your car as a daily. Road tires work quite well even in cold temperatures, whereas slicks and semi slicks need to be warmed up.
The indentations and grooves in the tread also make it far superior in wet conditions. If you are not too serious about racing in your BMW, or if you want to make your BMW M3 more practical, the performance road tires have the perfect mix of characteristics. They are cheaper to buy, last longer, and are safer for everyday driving. A benchmark for a performance road tire is often considered to be the Michelin Pilot Sport 4S.
Tire Compound
Tires that are intended for use on the track can often be had in different compounds. Simply put, the type of compound refers to the type of rubber used and the hardness of the tire. Usually, they are categorized as soft, medium, and hard.
As a general rule, softer compounds are less durable, so you will have to replace them more often. With soft rubber, there is also a greater risk of fold-over. On the other hand, they give you better traction even on low-grip surfaces and lower temperatures.
A harder tire compound can be characterized as the opposite of this. It does not provide as much traction, making your car easier to slide, and usually needs higher temperatures to stick properly. On the upside, they can survive a lot more laps. A hard compound might also be more suitable for heavier cars.
Closely related to the hardness of the compound is the stiffness of the sidewalls. A stiff sidewall generally improves the responsiveness of the car, and it does not wad up as much as softer sidewalls. On the other hand, a stiff sidewall is not always the best choice, as it can decrease the stability of the car.
Tire Size
Of course, you will need to match the size of the tires to the wheels you have. It is important to consider the width of the tire, not only in relation to the wheels you have but also because getting ones that are too wide might decrease the performance of your car.
It is a common belief that wider tires have a larger contact area with the road, but this is not entirely correct. A wider tire only changes the shape of the contact area to one that is wider and shorter. However, a wider tire usually allows you to run on lower pressures, which does result in an increased contact patch with the road. This improves the grip and reduces the tendency of the car to slide around in corners. It makes the tires less prone to overheating but at the same time, the tires take longer to get to the correct operating temperature.
The tire width also affects the braking performance. A wider tire will help to translate the immense stopping power of high-performance brakes and decrease your braking distance. If brakes are something you are looking to upgrade on your car beside the track tires, visit newparts.com, where you can choose from a wide range of brakes from renowned manufacturers and get assistance in choosing the best brakes for your track BMW. On the other hand, track day tires that are too wide will have a significantly higher rolling resistance and slow your car down.
Just as important is the diameter of the tires, as it affects the rotating mass, the way ABS and traction control work, the effective gear ratio, and more. However, properly assessing the diameter you want for a track requires a lot of experience, so it is best to stick to the factory dimensions.
Choose Your Track Day Tires Wisely
Tires are a cornerstone of every track car. It is the one often overlooked component that can make or ruin the handling of your car. Compared to standard tires, track day tires are more expensive, and they also wear out faster, but the difference in grip is astronomical.
While the vast range of tires can seem overwhelming at first, it gets much simpler once you know exactly how you want to use your car. Although there are many more variables than we have covered in this article, such as tread wear rating, temperature grades, the total tread surface area, and we could also talk about how tire pressures affect the setup of a car, or why inflating tires with nitrogen might give you a slight improvement, it is not what you should be worried about if you just want to enjoy an occasional track day.
Choosing a proper set of tires for your BMW will ensure that you can get the most fun out of the track experience and also the most out of your bimmer. This guide should give you all you need to know to do that.
