Car Tyre Terminology

There are a lot of confusing names and terms used in the tyre market and we know that these can cause a lot of confusion along the way. To make you more confident in buying tyres online we have compiled a straightforward list of terms that may pop up when buying your tyres. The list is in alphabetical order to make finding the term a lot easier.

ALIGNMENT - This is a measure of how straight your tyres are in a vertical measure. If your tyres are out of Alignment the drive of your vehicle can become shaky and this will increase the wear on your tyres. It is always recommended that you get your tyres aligned when you get them fitted.

ALL SEASON TYRES - This are tyres that can be used all round.

ALLOY WHEELS - You wont find alloy wheels on every vehicle. Van and trucks very rarely have alloy wheels but you will find them on many cars today. They are made from a mixture of Aluminium or Magnesium, which makes them lighter than the normal steel wheels you see on cars. They are also much better when it comes to safety and performance.

AQUAPLANING - This is not a good situation to be in. Aquaplaning is when the vehicle drives through a layer of water on a road surface, which can lead to the vehicle sliding in an uncontrollable fashion. This mainly happens after heavy rainfall and can lead to many accidents on the road. The best thing to do if you ever find your self-aquaplaning is not to break, keep a firm grip of the steering wheels and direct yourself out of the water on the road.

ASYMMETRIC - This relates to the pattern of the tread on your tyre. Asymmetric patterns are pattern that are different from one side of the tyre to the other. If you buy Asymmetric tyres it's imperative that they are fitted with the correct directional pattern heading in the correct direction.

BALANCING - This is what the tyre fitters do to the wheel and tyre as soon as they have been fitted together. The tyre fitter ensures that the wheel balances so that when you travel at any speed there will be no vibrations and shakes.

BAR - This is a measure of air pressure. Its like psi but much greater. In fact 1 metric unit is the equivalent of 6.8947 psi.

BLADES - if you where thinking these were wiper blades there not. They are actually the slits in the tyre grip. The slits have been added to the pattern of the tread to increase grip in the Winter when conditions are pretty awful.

BUDGET TYRES - these are tyre tyres that are a lot cheaper than the tyres that you may have heard about. They are the cheapest of the tyres and with this come with a lower level of performance.

CENTRE-LESS ALLOYS - You will only find these alloys on either Citroen or Peugeot vehicles. As a design feature they created the alloys with no centre. This limits the numbers of garages in the UK that can actually balance the wheels because a specialist adaptor is needed to do this.

COLD INFLATION PRESSURE - This is the pressure of the tyre when the vehicle hasn't heated up. It is measured before the vehicle has been driven.

COLD WEATHER TYRE - These tyres have been designed to work better in lower temperatures; they work best in temperatures 7 degrees and below. Always a great asset for any vehicle in the UK, we all knows how long the winter lasts!

CONTACT PATCH - this is the direct area of the tyre that comes in contact with the road.

ECONOMY TYRES - This is another term for Budget tyres. These are the cheapest tyres on the market. Although cheap they usually don't have great performance.

FOOT PRINT - This is another name for contact patch. It is the area of the tyre that makes contact with road. Similar to the sole of your shoe.

INNER LINER - This is a term that describes the layer of rubber, which can be found in the tubeless tyre. This liner stops air pressure from leaving the tyre during use.

LOAD INDEX - This is the weight each tyre can carry at the speed that is outlined on the speed rating of the tyre. The Load index is highlighted as a number on the tyre wall.

LOW PROFILE TYRES - You will see low profile tyres on most sports cars, They are defined as tyres with a small sidewall. These are used not only for aesthetics but also because they help the handling of the vehicle.

MAXIMUM INFLATION PRESSURE - This is the Maximum pressure a tyre can withstand and operate safely. Under no circumstances pump your tyres above the Maximum Inflation Pressure.

MID RANGE TYRES - These tyres are seen as middle of the market tyre. They are more expensive than the Budget tyre range but not as costly as the Premium range. The performance as you most likely suspect is also middle of the market, reliable but not the best.

ORIGIANL EQUIPMENT - This term is used to describe the original wheel/alloy and tyre that came on the vehicle form the manufacturers. Many vehicles on the road today don't come with original tyres or alloys, they have been upgraded by an owner throughout its life

OVERSTEER - If you have ever had the pleasure/panic of the sliding feeling when your back tyres loose grip and slide out, well this is oversteer! It usual happens when cornering but is more likely to happen in bad conditions or with worn out tyres.

PROFILE - This is the height of a tyres sidewall. If you look at our Tyre Size Guide you will see that the sidewall is measured as a percentage of the tyres width. It can be quiet confusing but check out the Tyre size guide and all will be explained

PSI - This is the measure of Air Pressure - PSI actually stands for "Pounds per Square Inch"

RADIAL TYRE - Te radial tyre design is explained in our Tyre Technology section on the site and as it happens its one of the biggest revelations within the tyre market today. All cars today on the road will be fitted with radial tyres, that's unless it's a Classic from back in the dark ages!

REINFORCED TYRES - This is when the tyres have been designed to withstand greater pressure on the sidewall of the tyre by making the rubber thicker. These tyre are usually seen on bigger heavier vehicles, most 4x4's have Reinforced Tyres.

REMOULDING - This is when an old tyre is part recycled. The original tread from the tyre is removed and a new tread is added to the old casing of the tyre. Making a nearly but not quite new tyre. We would advise not buying remoulded tyres as a general rule.

REPAIRABLE AREA - This is the area on the tyre that can be repaired from a puncture. Not all sections of the tyre can be repaired; if the puncture is to close to the sidewall then unfortunately its game over and a new tyre will be needed.

RETREADING - This process is part of Remoulding. New tread is added to the casing of the tyre.

RIM - This is the very edge of the wheel, the section that is most likely to get scuffed on a curb when reverse parking! It is also there to hold the tyre in place on your vehicle - Pretty important!

RIM DIAMETER - This is another word for Rim Size - it's the measure of the rim from one edge to another - The diameter.

RIM SIZE - Again this is mentioned in the Tyre Size Guide. This is the measure of the diameter of the wheel. It is measured in Inches and is the final section of your tyre size; it will be shown on your tyre with an "R" in front of it.

RIM WIDTH - if you were to take the tyre of the wheel the rim width is then visible. It is the measurement from one side of the wheel to the other; don't get this confused with the Rim size.

ROLLING RESISTANCE - if you want a very fuel-efficient tyre then you need to look for a tyre with a Low rolling resistance. Rolling resistance is a measure of the energy used to keep the tyre rolling at a steady speed.

RUN FLAT TYRES - You will find a lot of information on these in the Tyre Technology section of this site but as a quick reference they are tyres that have built up sidewalls allowing the driver to be able to carry on driving on the a tyre that has a puncture for up to 100 miles at up to 55mph. Remember though the tyre will have to be replaced as soon as possible.

SECTION HEIGHT - This is the measurement of the height of the tyre. Its measured from the rim of the wheel to the top of the tyres treads.

SECTION WIDTH - This is like the measurement of the Rim Width but it's the measurement of the tyre from one side to another.

SHOULDER - yes this isn't an actual shoulder but the area of a tyre where the sidewall meets the tread.

SIDEWALL - If you look at the Tyre Size Guide (link) you will see the information about the sidewall. In a nutshell the sidewall of a tyre is the section that you can see when looking side onto your vehicle. It has all the tyre size information about the tyre on the sidewall.

SIZE - This is the actual measurement of a tyres size. The most common UK tyre size is 205/55R16 - mostly found on medium sized vehicles.

SNOW TYRES - as the title suggests these are tyres that are specifically designed for the snow. Their tread has been designed to work to great effect in very harsh snow conditions. It's actually very surprising how great these tyres actually are.

SPACE SAVER OR SPAVE SAVING TYRE - these are small tyres that you may see on cars occasionally after they have had a puncture. They are designed to be small so they fit somewhere on your vehicle and are seen a temporary solution but these don't make for great tyres so as soon as you can get back to rolling on the correct tyres for your vehicle.

SPEED RATNG - This is the measure of how fast a tyre can travel at when loaded up to the specified load rating.

STEEL RIMMED WHEELS - these are the wheels found on many cars that haven't been upgraded to alloy wheels.

TRACTION - this is another word to describe the grip a tyre has on the road or track.

TREAD - The tread is the part of the tyre that is in contact with the road. There are many different designs out there, some catering for all weather, some for racing and others for general use.

TREAD DEPTH - the Tread depth is the amount of tread measured in millimetres that is on a tyre. Winter tyres in the UK come with 12mm of tread where as normal tyres come with 8mm. If your tread were to go below 1.6mm you would in fact be breaking the law. Remember to always check your tyres and save your self a hefty fine, 3 points and a possible accident.

TREAD WEAR INDICATOR - these are visible on the tyre and act as an indicator as to when the tread of the tyre is getting low. As soon as the tread drops lower than 1.6mm they become visible and are found in the tread groves of the tyre

TYRE INFORMATION - This is either found on the inside of the driver's door or in the vehicle handbook. It will tell what pressure to pump your tyre too and how much your tyre can cater for.

TYRE PRESSURE - This is pretty much self-explanatory, it's the pressure of the air that is inside the tyre. In the UK it is measured in PSI. It's really important that you have your tyres inflated at the correct pressure.

TYRE PRESSURE MONITORING SYSTEM - Some vehicles have these fitted and other don't, they act as an alarm system that will notify you when there has been a drop in pressure In the tyre.

TYRE WALL - This is another name for Sidewall. It's the section of the tyre that you can see when looking side onto your vehicle. Its also has all the information about your tyre size on the Tyre Wall.

UNDER INFLATION - This is when a tyre is low in air pressure - if your tyres are under inflated its time to pump them up. Not only is it unsafe but you will also be wasting fuel because of an increase in rolling resistance.

UNDERSTEER - If you have ever been in a vehicle and got under steer you will know all about it. It's when you turn the steering wheel to go in another direction and the vehicle carries on moving straight. Not the best situation at all.

VALVE - This is the section on the wheel that will connect to the air pump and allow the user to pump the tyre up. It can be used to release pressure as well.

WINTER TYRES - If you could ever make a good investment winter tyres would be them. These tyres are specifically designed to work well in conditions of 7 degrees or below. A brilliant invention and can prove to be a real lifesaver.