5 things you need to know about tyres


You drive on them almost every day. You replace them once or twice a year. You might have had to change one yourself, or maybe you’ve done a good deed and helped a friend in need. But apart from the fact that they are round, black and essential for safe driving, what do you really know about tyres? Read on to learn 9 fascinating facts tyre that you can use to impress your friends.


1. What do all those numbers actually mean?


The first question you’ll almost always get asked at a tyre fitter when you go to buy replacements is what size. If you are like most people, you’ll immediately find yourself going back outside to check. If you mix your numbers up and ask for a set of 255/50 R16’s instead of 205/55 R16’s for your mid-range family car, you’ll likely get an odd look from the salesperson. So what do all the numbers on the tyre actually mean? Here’s how they work:

Example: 205/55 R16

205 – The width of the tyre in millimetres. Most standard car tyres range between around 205 – 225 (the 255’s you just asked for are very wide).

55 – The profile. In layman’s terms, this is the height of the tyre wall as a percentage of the tyre’s width. The lower the R-value, the lower the profile of the tyre.

Interesting fact – Be aware that ultra-low profile tyres can affect your speedometer reading.

R – Radial construction

16 – The diameter of the wheel rim in inches


2. How old is that tyre?


As well as the tyre size details as explained above, a close examination of your tyre will also reveal the word ‘DOT’ followed by an alphanumeric code and then a 4-digit code. For example, it may read ‘DOT J3EX 4417’. The alphanumeric code denotes the factory of production (Matador AS factory, Puchov, Slovakia in this example) and the 4 digit code the date of production. The first two digits give the week and the second two the year. So in this example, 4417 means that the tyres were produced in week 44 of 2017 (30th October to 5th November to be precise).

You probably have no reason to ever need to check this – but we guarantee you won’t be able to resist it from now on!

On a more serious note, it is worth noting that a tyre is generally considered to be safe for 5-6 years from the date of manufacture, so if you are driving a vehicle with tyres of unknown origin, it could be well worth a check.


3. Correct inflation improves safety and saves money


Under or over inflated tyres can lead to many different problems, but most importantly the correct level of pressure will ensure that your tyres offer the maximum possible level of safety for you and your vehicle, as well as optimising your fuel consumption and therefore saving you from overspending unnecessarily. As well as this, incorrect inflation will reduce the longevity of your tyres, also increasing your overall running costs.

A drop of 6 psi may not appear to be significant on visual inspection, but in real terms is a reduction of almost 20% in pressure – and it can have a comparable effect on the reduction of the tyre life.

Bear in mind that the outdoor temperature can also affect your tyre pressure – a drop of 10℃ can cause your pressure to drop by around 1 psi. This is why you may find your tyre pressure light suddenly come on on the first frosty morning of the year.

To check the correct tyre pressure for your vehicle, consult the manual or check the information panel inside the door frame.


4. What is the legal tread limit of a tyre?


Despite a huge increase in awareness of tyre tread limits in recent years, many drivers are still not aware of the actual legal limit and how to check it. The exact limit set by law is 1.6mm. Although there are many coin based methods for measuring your tread level, the best way to check is to use a purpose made depth gauge which will give you a much more accurate reading.

New tyres also now come with tyre wear indicators. These are raised sections between the tread. As a rule, you should replace your tyres before the tread wears down to the level of these indicators.


5. Why do new tyres have the same stickers as my electrical appliances?


You may well have noticed that new tyres always have stickers on them that appear to be identical to what you now find on the front of electrical appliances such as refrigerators or washing machines, as well as on the packaging of a light bulb.

This is part of an initiative introduced by the EU to help consumers make more informed choices when it comes to the environment.

For tyres, the labelling system was made compulsory in 2012 and must tell you the relative fuel consumption, wet grip and noise classification.

For the best choice in tyres at the best possible prices across Dublin, get in touch with your local branch of Tyreland today. Call us on 01 860 20 20 to speak to a member of our team.

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