Tyre Size Guide Helps You Determine The Exact Tyre Size For Your Vehicle

Have you ever gone to buy tires and been baffled after looking at the size chart? It can be rather tricky looking at the Tyre Size Guide with those confusing numbers and complicated signs and having no clue what they signify. So, you end up trusting whatever the tyre seller tells you, and you purchase it. But that shouldn’t be the case. Hence, you may wind up buying ones that do not precisely fit your vehicle’s requirements.

How To Read Tyre Size?

Choosing the wrong tyres is wasteful and even unsafe. So, knowing how to determine the appropriate size for your vehicle may save you time, hassle, and cash. And as a car owner, this means a lot. So, if you’re buying your car’s tyre for the first time, here is your guide to understanding what those symbols and numbers actually mean. Let’s get started!

There are six divisions in the metric sizing of any tyre. They are as follows:

1. First letter

• The first letter in the tyre code indicates the tyre type and class. P designates a passenger vehicle tyre, including cars, SUVs, minivans, small pickup trucks, and sedans.
• LT class stands for Light Truck, for automobiles carrying medium loads, trailers, and different vehicles used for rough driving conditions. These tyres are also suitable for pickups and vans hauling heavy loads.
• ST means Special Trailer tyres designed for autos carrying heavy loads, utility trailers, and craft trailers.
• T is for Temporary rated or spare tyres for speeds that cannot exceed 50 mph and for emergencies.

It is most likely a passenger tire if there’s no initial letter. Therefore, make sure that you double-check the load rating from your buyer.

2. Width

• The 3-digit number written after the first letter is the width section. For instance, if 265 is mentioned on the tyre, it signifies the width from sidewall to sidewall in millimetres.

3. Aspect Ratio

• The aspect ratio, a.k.a. the tyre profile size, reflects the sidewall’s dimensions proportion to the section width. For example, ’50’ indicates that the sidewall is half the width.
• R-reading or Radial tyres now account for 98 % of all manufactured ones. Most car owners prefer them because of their enhanced grip, gas mileage, and durability. The plies of radial tyres are placed perpendicular to the direction of movement and indicate a mix of polyester cloth and steel layered with rubber.
• D-reading is present in some tyres. It is an indication for a diagonal ply or bias-ply, often known as the standard cross-ply.
• Another letter is B, which denotes belt constructions generally seen on bikes or trailers. They’re very similar to D, except they have a belt that passes beneath the thread region.
• F is another type that indicates ‘run-flat.’ Simply put, the tyre runs flat after being ruptured for a short distance.

4. Wheel Diameter

• The wheel diameter is a two-digit value denoting the wheel’s diameter in inches. It uses the same coding for Tyre Size Guide worldwide.

5. Load Index or Service Description Rating

• This rating is used to identify your load aspect and speed rating. Based on a conventional tyre chart, it indicates how much weight a tyre can hold.

6. Speed Rating

• This rating shows the maximum speed at which the tyre is safe to drive over an extended time. An excellent speed rating can withstand more heat. A high rating also indicates a higher price and a better quality tyre.

Reach Us Today!

These are the essential metrics to identify in any tyre. If you need help picking up the perfect one for your automobile, contact the professionals of AJAJ Tyres right away! We will be more than happy to help you.

CALL 0414 969 969

Frequently Asked Questions

1. How do I read my tyre size correctly?
Tyre size is usually written on the sidewall of your tyre and includes width, aspect ratio, and rim diameter. For example, a tyre marked 205/55R16 means the width is 205mm, the aspect ratio is 55%, and the rim size is 16 inches.

2. Why is choosing the right tyre size important?
The correct tyre size ensures safe handling, braking performance, fuel efficiency, and comfort. Using the wrong size may cause uneven wear, poor grip, or even safety risks.

3. Can I upgrade to a different tyre size than the manufacturer’s recommendation?
Yes, in some cases you can, but it’s important to stick within safe limits. Always check with a professional tyre fitter or refer to your vehicle’s manual before changing sizes.

4. Where can I find the correct tyre size for my vehicle?
You can usually find it in your vehicle’s owner manual, on the driver’s side door placard, or on the current tyre sidewall.

5. Do wider tyres improve grip and performance?
Wider tyres can improve grip and handling but may reduce fuel efficiency and cause more road noise. The best choice depends on your driving style and vehicle type.

6. How do I know when it’s time to replace my tyres?
If your tyres show signs of wear, damage, or if the tread depth is below 1.5mm (the legal minimum in Australia), it’s time to replace them.

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