What size tyres for my car and how to read sidewall markings?
Customers often come to us asking how to check their car tyre size.
In this short article, we give you all the information you need to understand the essentials of your
Kumho tyres. Rest assured, Latrobe Valley Bandag is always here to help, so just give us a call direct. Otherwise, we hope you enjoy this piece on
wheel and tyre sizes explained!
What is the correct size tyre for my car?
Good news - there is no guesswork involved. Depending on the make, you can find this information in the car handbook, the petrol cap door, or a sticker in the door jam.
Can I have different size tyres on my car?
Although technically, this may be possible in some cases, we strongly advise against having different car tyres on your vehicle.
You want identical wheels set in unison and perform as mirror versions of each other. Adding a different tyre creates an imbalance even if that difference appears almost negligible. And, when driving you and your family on the highway at 110km per hour, you don’t want even a fraction of imbalance.
Adding one ‘black sheep’ tyre to the mix could result in speedometer disinformation, compromised steering, accelerating and instability. It can also mean your car takes longer to reach the desired speed or come to a complete stop. All of these create the potential for an otherwise avoidable accident.
Finally, the wrong size might not even fit in the first place, so your money is wasted. Never guess and never go against the grain - speak to our specialists about the right
passenger vehicle tyre service
and product for you.
What do the numbers on a car tyre mean?
OK, so now you know how to check the tyre size for your car, let’s move on to how to read tyre sidewall markings. A tyre must have the following information available on its sidewall:
- The name or logo of the manufacturer and its country of origin
- Tyre size, series and rim size
- Speed rating
- Serial number
- Clarification of whether the construction is radial, tubed or tubeless
- Mould & factory code number
Tyre sidewall markings explained

You’ve probably noticed a long row of numbers, forward slashes and letters on your tyres. This legend corresponds to important information you and your tyre specialist require. Let’s take the above Kumho Tyres example.
- Tyre width
This figure is the width of your tyres in millimetres. - Aspect ratio
The aspect ratio is a percentage indicating the tyre’s section width compared to its section height. - Tyre construction
The letter indicates the type of construction used. This indicates the tyre can reach a maximum speed of 300km. - Tyre rim
Unlike the width, this figure is provided in inches and represents the diameter of the wheel rim. - Load index
Confirms the maximum amount of weight this vehicle can legally and competently carry and the speed at which it will operate safely. It’s important to note this is based on an assumption the tyre has been correctly fitted. - Speed symbol
This figure confirms the maximum speed at which this tyre can travel, T being 190km/h.
Why do you need to understand your tyre sidewall markings?
It’s good for you to have this knowledge to understand the options available. Of course, the team at Latrobe Valley Bandag will always provide you with plenty of choices regarding
new tyre
replacements. However, we like to empower our customers with knowledge as it often leads to good questions. And we like being kept on our toes!
Contact us for all your tyre service needs tact us for all your tyre service needs
Want more information? Whether you need professional tyre repair, replacement or servicing, contact the specialist. Our team is here to help you stay safe on the roads.








