A beginner’s guide to Car Tyres

Car tyres are a fundamental component of any vehicle; the single items which offer the most stability and grip on the road. With this in mind, it’s obviously important to keep them in perfect condition to ensure you get the biggest benefit for your new Ford vehicle. Because we want our customers to get the biggest benefit, here’s our complete guide on car tyres, which offers all the basic details you need to know.

Some common questions

There are so many questions when it comes to car tyres, and while they are essentially a membrane of rubber filled with pressurised air, so many know very little about them. Here are a few questions which you could find useful.

What do the numbers and letters on the side mean?

While it may look exactly like a random barcode, the numerical and alphabetical characters found on the sidewall of your tyre tell you everything you need to know about the tyre – if you understand what it all means of course.

It will always start with three numbers, such as 125, 165 or 185 – this is the width of the tyre in millimetres. The next two numbers represent the height of the tyre and is calculated as a percentage of the tyre’s width – which is also known as aspect ratio. The next is a letter which indicates the construction of a tyre’s fabric carcass. This will either be ‘B’, ‘D’ or ‘R’, indicating Bias Belt, Diagonal or Radial respectively. Next is the diameter of the tyres inner rim which will be shown in inches. The final set of numbers show the load index, identifying the maximum load capacity of a tyre when driven at maximum speed. Finally you will see a letter to show the maximum speed for the tyre when at full load, which is measured from ‘N’ at the lowest and ‘Y’ at the highest.  

What’s the difference between a summer and winter tyre?

The purpose of winter tyres is fairly self-explanatory, and while summer tyres can be driven for the majority of the year, winter tyres are designed specifically to offer enhanced performance during cold or icy conditions. They usually have a softer rubber compound, and are unmistakable thanks to the jagged slits which cover the read blocks – also known as sipes. Winter tyres also have a deeper tread groove than a conventional summer tyre, making them the perfect product to grip on the cold roads. If you are in the market to purchase a new or used Ford car in Andover, Dorchester or any of our other dealerships, be sure to speak to our team about the options on winter tyres we have available so that you’re prepared.

How do I know if they need replacing? 

The easiest method of working this out is through checking the tread depth of your tyre, the level of depth of the grooves in between the tyre; the more tread you have, the greater grip you will have on the road. The legal limit for the depth of tread across 75 per cent of the tyre is 1.6mm, but many experts recommend changing your tyres when your tread depth falls below 3mm to avoid picking up penalty points and a hefty fine.

If you want to know your tread depth for certain and would rather not guess, this handy tread depth gauge from Draper Tools could be exactly what you need. Pictured above, it offers a fast and easy method of accurately measuring tread depth to offer you complete peace of mind.

How do you find out your tyre pressures?

Tyre pressures are one of the most important aspects of any tyre safety regime, and keeping your tyres to the right level will help increase both the life of your tyre and your stability on the road. When we got in touch with Draper Tools for their number one tip on keeping your car tyres in the best condition, they recommended to check your tyre pressures every two weeks.

Draper Tread Depth Gauge

Car pressures are usually measured in PSI (Pound per Square Inch) or BAR – which relates to air pressure. While information on the exact pressures required for your vehicle can be found on various websites, the most accurate place to source this information from is on the vehicle itself. On new vehicles there will be a rectangle placard on the inside of the driver’s door, but this can also be located near the fuel filler cap or glovebox in other models. This placard will show you the recommended pressures for both front and rear tyres under normal driving conditions, but may also offer details on levels to adhere to for heavy loads and high speeds.  

If the placard shows the levels in bar rather than PSI, you will need to convert it into PSI for a more accurate reading. For a helping hand, 1 BAR is equal to approximately 14.5 PSI.

This guide should provide all the essential information you need to keep your car tyres in perfect condition. If you require any further assistance or require a specialist question, be sure to call a member of our expert team at one of our official Ford dealerships in Somerset, Dorset or other areas across Southern England.

Image Credit: Draper Tools

This content was written by Ben Edwards. Please feel free to visit my Google+ Profile to read more stories.

Tyre Pressure Gauge