Previously on CARS101, we talked about engine oils and everything related to the engine oil which includes viscosities, additives and every single stamp or certifications that the bottle carries. While that was far more in-depth than what I intended on publishing, it did however give me a better understanding as a consumer in general. However, engine oils are the sort of things where either you care enough to buy a specific oil or you just look for the workshop with an RM80 promo with a filter and labor for the sake of convenience.
That being said, tires are pretty much the same as well. There are a lot of big names with attractive patterns and then there are some “that’ll do” kinda tires that are so cheap that they seem very sketchy. Once again, there are a lot of symbols and ratings that have to conform to international standards but we reckon most consumers (including us) have no clue what this all means.
However, a normal road car’s tire is actually more complicated to understand as compared to something like on a Formula One car. In Formula One, compounds can be recognised by the color of the writing on the sidewall but on normal cars, there’s at least nine numbers, a few letters and potentially an Egyptian hieroglyph if you look at it hard enough. To top it all off, each and every single number and letter has a specific meaning.
Choosing Your Tires
Let’s start with the basics.
We’ve all been there, browsing from site to site, finding the best rubber donut to put on the car. Then comes the sizes. 195/50R15? 205/45R16? 225/45R17? Well, let’s break down each and every one of these numbers. As an example, we shall use a baseline of ‘195/50R15’ size and will highlight each number.
- The first three digits tell you the width of the tire in millimeters. These are to be considered if you intend to look for more or less grip. A skinny tire gives you less grip while a wider tire gives you the opposite effect.
- The next two digits are often referred to as the aspect ratio, or in simpler terms, the thickness of the sidewall. If a tire has an aspect ratio of 50, it means the tire’s height is 50% of its width. A lower profile tire provides better overall handling however a higher profile provides better comfort.
- The ‘R’ stands for the construction of the tire which is usually ‘radial’. However there is also a ‘D’, which means ‘diagonal’ but is rarely seen on regular tires.
- The last two digits are referencing the diameter of the wheel, which in this case is a 15-inch wheel.
Types Of Tires
If you go on Google and write down your tire size, most likely you’ll be shown quite possibly the cheapest option there is on e-commerce websites. However, don’t be fooled. Not all tires are the same as there are things such as summer tires, winter tires, mud+snow or ultra high performance (UHP) tires etc. While winter tires and mud+snow tires are absolutely pointless here in Malaysia, that doesn’t mean some tire shops won’t sell them to you for cheap.
Most tires on the road here in Malaysia are in fact summer tires, well let’s face it, it’s summer 365 days a year here anyway. But because of that, most tires for sale here are claimed to be UHP tires. That being said, this is a topic which manufacturers can blatantly claim whatever they want. This comes down to the treadwear ratings as UHPs are generally 300 and below before they get into the ultra-ultra high performance (UUHP) range.
You may have also heard about run-flat tires which are mostly used on luxury cars. As the name suggests, these tires can be used even when they are completely deflated and flat, hence reducing the need to get them replaced at the side of the road in the case of any emergencies or a flat tire as you can just drive-off to a nearby petrol station. No, these are not bulletproof tires and you still gotta fill them up when they’re flat. However, these tires are often found to be very harsh for city driving as well as impractically expensive to be used more than once. Most owners often move back to conventional tires once the run-flats are worn out.
Don’t get fooled by the pretty patterns on tires as well, while most do serve a purpose to channel water in the damp and wet, some cheaper options are just there to look good. Remember, a soft compound is what gives you grip and not the pretty pattern. That being said, asymmetrical or directional patterns do play quite a role in this factor.
Directional or Asymmetrical?
Now, regular consumers would never question this but it’s good to have some knowledge whenever you’re getting new tires. With directional tires, these are primarily targeted for wet traction as the tires are designed with a ‘V’ pattern which serves as a water channel. The water channel allows water from the centre of the tire to be pushed out to the edge of the tire, making it good for wet traction. Directional tires usually display an arrow or a ‘right side or left side’ marking on the sidewall to show the direction of rotation to eliminate any form of confusion during installation.
Asymmetrical tires however are usually tires with a tread pattern that is designed to achieve a bit of everything at a time, hence its design is usually different on both sides of the tire. It’s a split-pattern with the outer large surface area meant for dry traction while the smaller inner pattern focuses on wet traction. However, this makes it easier to rotate tires which we will get into later in the article.
Treadwear, Traction and Temperature.
These three factors are the next few things to consider when purchasing your next set of tires. However, let me be frank as these three factors are not governed or rated by any third-party association. These are just numbers and ratings that are given by the manufacturers themselves, so it may vary from tire to tire and brand to brand.
‘Treadwear’ for example is the rough gauge to know what kind of purpose the tires are meant for. A lower number usually means the tires are soft compound which indicates the tires are focused for track use rather than the normal day-to-day usage. That being said, a lower treadwear does wear out faster than the higher rated treadwear. But then again, a higher treadwear provides harsher ride quality as well but they do tend to last a very long while.
For traction and temperature however, these are usually rated with the letter ‘A’. With more ‘A’s in the rating, means that the tire tolerates better. But then again, a higher rating also equates to a tire more suited for a beating in the track. But unfortunately, having the highest rating on a soft compound tire with a high treadwear is close to impossible.
Getting The Latest Stock
As a consumer, you’d most likely want anything that was recently produced. If possible, we’d even want something that is still hot off the production line. However, as usual, not everything in life can be acquired the way we want them, so, more often than not, we have to make do with what we have. But is getting something that has been produced for quite some time necessarily be a bad thing?
No, not really to be honest. While there really isn’t a scientific study that has been conducted to show the effects of an unused aged tire, it is not recommended to use any tire that has reached a five year mark since its manufactured date. While you may get them slightly cheaper, why take a risk on something that’s actually keeping you from crashing?
So, how do you check whether the tires are new or have been sitting there for awhile? Well, it’s actually pretty simple because every tire will have the same stamp. First, just look for the word ‘DOT’ and you’ll find the dates next to it. These are just four digits that indicates the week and year of manufacture. The first two digits means ‘week’ while the last two digit means ‘year’.
For example, if the digits say “4312”, the tires were produced on the 43rd week of the year 2012. Where as if it says “2022”, it’s the 20th week of the year 2022. Simple but effective.
Stretching The Tires
In case you’re thinking about stretching the tires for a stance vibe, by all means, do as you please. While we aren’t really the best advocates for the stance community, we try to respect all builds the best that we can. However, just know that there are legal limits to stretching your tires and the authorities won’t care no matter how you justify. But whatever you do, just don’t stretch the tires to the point of exposing your wheel barrel.
Knowing Your Tires.
Well, you just bought tires? Cool but do you what do these symbols mean?
Hold On, There’s More.
While those initial numbers for sizes are often what we care for the most, there are a few more things that may seem familiar but what do these actually mean? I’m actually talking about the speed rating and load index, another number and letter after the size indicator. While these are not usually cared for by the general public, any speed demon should consider these numbers as each tire has different capabilities.
For example, you may have seen after the ‘195/50R15’, there is another ‘91V’ or ‘88U’. These are the said speed rating and load index. The number explains the load while the letter explains the speed. These numbers and letters don’t necessarily make sense in any particular order but I’ll try my best to explain how they actually work.
Let’s start off with the term ‘Speed Rating’. Speed Rating is the maximum speed for a tire when it is correctly inflated and being used under load. The speed rating is the letter at the end of the sidewall, after the load index number.
|SPEED RATING||MAXIMUM SPEED|
For example, if the tires have the symbol ‘H’, the tires are only capable of withstanding the maximum speeds of 210KM/H.
Load index however explains the maximum carrying capacity of the said tires. These numbers often relate to the weight of the car itself as well. These figures vary from tire to tire. For example, a tyre with a load index of 91 can carry 625kg of weight. Unfortunately due to the various amounts of numbers for the load index, I couldn’t be bothered by it. And if I couldn’t be bothered, I doubt someone would.
All in all, when combined, a 195/50R15 91H tire, for example, is a 15-inch diameter wheel on a 195mm radial tire with a 50% thickness that is capable of withstanding 625kg at a maximum top speed of 210KM/H. These are factors to consider when getting new tires.
What Are These Dots On A New Tire?
If you are someone like me who tends to be a bit nosy whenever you’re at a tire shop, you may have realised that new tires often have painted dots on the sidewall. Now, these dots are not actually placed randomly by the shop. The dots actually serve a purpose for the mechanic who is mounting your tires and are actually placed there by the tire manufacturers themselves to minimize the usage of weights for tire balancing.
Now, these dots are usually colored in red or yellow. As for the red dot, it often indicates the tire’s high point. If you are confused, not to worry, as this does not really affect you unless your mechanic is untrained. Which brings us to the second color, the yellow dot. The yellow dot has to be aligned properly with the valve stem as the yellow dot indicates the heaviest point of the wheel. With all of these combined should minimise the use of wheel weights which in turns gives you a more balanced wheel and a longer-lasting tire.
What do you mean tire maintenance? It’s a tire, just fill it with air, right? Right? Well, no. Not really.
You might not believe it but I get this question more often than I actually want to answer as most of my friends have no interest in cars. So, let’s start with the big one, ‘how often should I check my tire pressure?’ Well, that depends as some manufacturers even recommend that you check your tires at least once a month while some owners just check them if the car feels ‘extra’ stiff.
That being said, there are quite a few factors to keep in mind, such as the weather, frequency of drives and the weight of the car. Another factor to keep in mind is that air molecules expand when it is heated which in turn increases the pressure inside the tire. This in turn works vice versa when there is a drop in temperature. But having a Tire Pressure Monitoring System (TPMS), be it a built-in unit or an additional accessory, it makes your life just a tiny bit easier in the long run.
If you are unsure about the required tire pressure for your car, just check at one of these three locations which should indicate list down the appropriate tire pressure. (NOTE: Not all cars are have them in these locations)
- Driver door sill
- Fuel tank door
- Owner’s manual
And before you panic, there are also three types of pressure units used on cars. These vary from car to car and can be rather confusing at the petrol station when you are inflating tires. If you are still unsure, there is always a ‘information’ button or ‘i’ at the air pump which automatically converts the pressure unit. Among the pressures used are:
- PSI i.e. 32PSI
- KPa i.e. 220KPa
- Bar i.e. 2.2Bar
In case you are still unsure of the pressures used, maybe due to larger aftermarket wheels, you can always consult a professional at a ‘tire shop’.
Taking The Tires To The Track
Well, this won’t be one of our articles in I don’t talk about taking the car to the track but hey, if we don’t, then who would? Tracking your car is absolutely fine, just know what you’re doing. But on track, just bare in mind, that your tires will require some heating up to do before you can give it a proper beating. Cold tires just mean bad news.
Lower your tire pressures if it’s a hot day as it will heat up and expand the air inside, practically inflating the tires by itself. Also keep in mind that on-track debris like bits of other people’s tires will get stuck to your hot tires after a while. This will be rather annoying and takes quite a bit of effort if you intend on keeping them clean.
Tire balancing is primarily done to distribute weight equally around the entire tire (pun intended). Anyways, wheels that are out-of-balance can cause uncomfortable vibrations while driving. This combined over thousands of kilometers of use, will eventually lead to premature wear on suspension and steering components. Just a small amount of weight makes an actual difference.
No, this isn’t the same thing as balancing. Alignment however is a completely different topic which would go under suspension components. However, to simplify the issue, an alignment should be done every now and then just for you to keep everything intact. Especially if your car pulls or sways to a specific direction, an alignment will definitely most, if not, all your steering issues.
Tire rotation is something a lot of people take for granted since it’s wear that happens gradually over a long period. And once you notice the problem, it probably means that it’s a bit too late for you to fix it. However, it should be done every now and then. While there isn’t any specific gauge on when you should rotate the tires, it’s best to rotate at every engine oil service interval or roughly 10,000km.
That being said, this also goes back to what kind of tires you own i.e. directional tires or asymmetrical tires. Directional tires can only be rotated from ‘front-to-back’ while asymmetrical tires can be ‘cross-swapped’. This is only due to the design of the tread. An asymmetrical tire will wear more evenly as compared to a directional tire, in case you are wondering.
My 10-year old spare tire is fine. Sure.
For the safety of you and your passengers, just go and inflate your spare tire whenever it crosses your mind. You never know when you will need it, so, it may come in handy to know that it is usable whenever you are in an actual emergency.
We’ve all been there so I know how frustrating it is, especially when you’re about to leave for work in the morning. These are such an unnecessary hassle that it essentially ruins your day once you see it. Especially on softer compound tires, they’re just like a magnet for nails or any sharp objects. However, it is completely safe to get the tires patched by a trained professional.
Patching punctures which are caused by small nails are fine but if there is a tear or maybe something that is wide, do not take a risk with a patch. It is unsafe and irresponsible to drive on a large tear. Swollen tires too are a big no-no. With tires, anything that looks risky, is risky, so just get them replaced as soon as you can, if not, immediately.
Your tires will eventually wear out and depends on how your use and abuse them, they may actually wear out faster than expected. However, you can check out the wear indicators on the rib of the tires. These are usually buried in the grooves but if they are already on an equal height with the rest of the tire, it may be time to change your tires before it gets too dangerous.
Always know the limitations of your self and your car. While we can try to educate the public (as well as ourselves), it all comes down to you behind the wheel. We hope to put more technical aspects of everyday regular products soon but til then, stay tuned for the next CARS101.
Written by | Danial Malek
Images by | NoEqual & Google