Replacing Tyres in Axle Pairs is Important

Getting tyre punctures can really dampen your day. While we're sure you're aware that getting your tyres replaced as soon as possible (and not just repaired) is a good idea, did you know that it's also important to get tyres replaced in axle pairs?

Which wheels are in axle pairs?

Most simply, axle pairs are the pair of wheels on each axle. The two front wheels of your car are an axle pair, as are the two back wheels.

As they share an axle, the wheels in an axle pair share loads and stresses between them, which is why they need to be proportionate to each other. Think of it in terms of a seesaw, except you want both sides of the seesaw perfectly balanced.

Why do tyres matter in axle pairs?

Well, the tyres absorb a huge amount of stress from road driving. In an ideal situation, you would want both wheels to operate in complete harmony, turning at the same speed and in exactly the same direction.

But in the real world, this is rare. That's because the condition of a tyre affects a whole host of variables that can impact the wheel's movement.

For example, how inflated a tyre is will change the effective diameter of a wheel. This then has a result on the turning rate of the wheel, as smaller wheels make more rotations, compared to larger ones that are turning at the same speed.

If this seems complicated, think about two people running: a child and an adult. The child, being significantly shorter, is going to have to make many more steps to run at the same speed as the adult - because the longer legs of an adult enable them to cover more distance per step.

So this variation in rotation between two wheels on an axle pair causes an uneven force to be applied across the axle. Eventually, this leads to premature wear on things like the suspension bushings, bolts, and other fixtures.

The tread pattern has to match

The tread pattern on tyres is engineered to channel water away from tyres, allowing your tyres to maintain contact with the road surface at all times.

Another reason to change tyres in axle pairs is that the tread pattern needs to match. If, for example, tyres in an axle pair were installed in opposite directions, the wheels would be working against each other when channelling water away.

Even when installed correctly, different tread pattern types are designed to channel water in different ways, so if you have different patterns on different ends of the axle pair, then there's still going to be an uneven force on the axle.

More immediately, you'll have lowered handling on your car, but in the long run, you'll have to replace both tyres from wear much sooner than you'd expect to.

Replacing Tyres in 4x4 vehicles

In 4-wheel drive vehicles, you rely on all of your tyres for traction and grip. So if any are out of balance, it then affects all of the others.

As such, we recommend that you replace all of your 4x4 tyres when one becomes degraded.

It's vital, however, that you check the weight rating of new tyres. Larger four-wheel drive vehicles are often designed to be able to carry more weight, and installing under-rated tyres could lead to a dangerous blowout.

When do I need to change my tyres?

You may not have a puncture, but if your tyre tread has worn too thin, then it could be time to replace your tyres.

The easiest way to test this is with the 20p test: you put a 20p coin in the tread groove and if you can see the border of the coin then the tyre has worn below the legal minimum which means you should get the tyre replaced as soon as possible.

Even though 1.6mm is the legal minimum, we highly recommend that you replace your tyres at 3mm tread depth in wet weather. When you think about the depth of most puddles on the road, they're usually deeper than 1.6mm - so waiting until your tyres have reached below the legal tread limit can still put you at serious risk of aquaplaning.

Need to order new tyres?

The quickest and easiest way to replace your tyres is to buy tyres online. Shop our huge range of tyres at the best price. Simply:

  1. Locate our Tyre Finder on the homepage or visit Buy Tyres in the menu
  2. Enter your registration or tyre size
  3. Add tyres to your basket
  4. Place your order online
  5. Book local tyre fitting at a time convenient to you

We recommend all customers check the tyre size on the side wall of their existing tyre before placing their order.

Alternatively, call or visit the garage and one of our expert specialists will help you find the right tyre at the right price.