5 Things You Didn’t Know About Tyres

When it comes to car maintenance, there’s so much to think about that some things can get missed. Tyres are one of the most commonly forgotten car parts, even though they’re one of the most important. Paying attention to your tyres won’t only save you time and money in long the long run, it will also keep you safe on the roads.

The black rubber at the bottom of your vehicle may seem simplistic, but there’s more to know than you might think. Although professionals like Bridgestone can help with all your tyre needs, knowing how they work isn’t only smart but actually really interesting too. Here’s five things you may not know about your tyres.

How to read your tyre size

The numbers you may have noticed on your tyres are actually important and help tell you what size they are! Let’s use 215/60R15 as an example.

215: Section Width

This is the width, in millimeters. A tyre’s width has to match the wheel it’s being put on.

60: Aspect Ratio

This is the percentage of the tyre’s sidewall height compared to the tyre’s section width.

R: Construction Code

This indicates the tyre is manufactured with a radial ply construction.

15: Rim Diameter

The diameter of the rim is in inches and is measured from one side of the wheel flange to the other.

What the minimum tread level is

The legal minimum tread for tyres is 1.5mm, so it’s important to keep an eye on. This is quite easy to check as all tyres have wear indicator bars on the tyre tread. You can find these at the bottom of the tread groove around the tyre. If these bars are visibly worn it means the tyre needs to be replaced.

How long you can drive on your space saver spare tyre

You have have noticed that space saver spare tyres, or donuts, tend to be smaller than regular tyres? This is mostly for convenience as they’re lighter, don’t take as much space in a boot and are easier to change.

The problem with this is that they lack durability and stability — which also means they lack safety. You should never drive faster than 80 km/h on a space saver spare because the handling may be compromised. Your car simply wasn’t built to drive safely under these conditions. Attempting to use a space saver spare long term will also put strain on your other tyres — as they will wear unevenly — as well as your engine which will need to work harder to accommodate the mismatched sizing.

What the patterns on the tread do


Featuring the same pattern and continuous grooves across an entire tyre, these are the most common type of tyres. You can find these on the majority of non-high performance cars. Known for their longevity and versatility, non-directional tyres can be rotated in a number of ways, which adds to their convenience.


Featuring a large v-shaped pattern with large grooves that are designed for water drainage — this is extremely helpful to reduce hydroplaning.


These semi-hybrids can generally be found on sports cars and come in multiple tread patterns. This maximizes the grip and stability on both dry and wet roads whilst still allowing great cornering.


If you’re after a bit of everything, these tyres may be for you. Discharge water with the V-shaped pattern whilst still get dry road performance from the asymmetrical tread.

How punctured tyres are repaired

Punctures can generally be repaired, so long as it isn’t through the sidewall of the tyre or is larger than 6mm. Tyres also won’t be repairable if they are worn below the wear indicator bar.

A tyre is actually repaired from the inside out — it is first deflated and removed from the rim before the casing is sealed where the puncture occurred, making it airtight again. It’s then refitted to the rim of the wheel and put back on your car.

For more information on Tyre Care and Maintenance visit the Bridgestone website.

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