The only difference between most types of tyre is the tread pattern (and the name and specification markings on the sidewalls).
Just looking at the tread pattern even though some look great won't tell you which ones grip best, give the best fuel consumption or last longest.
Before you start looking for the tyre which suits you, you'll need the basic information about what tyres your car needs. You can only fit the size and specification of tyre recommended by the manufacturer for the wheels on your car.
Never ever fit tyres that are a different size or speed rating from those specified by the car manufacturer, you might end up having a accident! Please don't use a mixture of tyre types without first checking your car's handbook, or asking a reputable dealer.
Car tyres' sidewall markings
How many people actually know what the markings on your tyre?
Understanding the markings on the sidewalls of car tyres will help you to choose the right ones for your car. Here's a guide to how tyres are classified, using the 205/45 R18 T, as an example:
205 - tyre width in mm
45 - tyre sidewall profile - sidewall height expressed as a percentage of its width
R - radial (rather than a cross ply)
18 - diameter of the wheel rim, in inches
T - speed rating which must match, or exceed the maximum speed of your car.
Tyre speed ratings:
S 180 km/h or 112 mph
T 190 km/h or 118 mph
U 200 km/h or 125 mph
H 210 km/h or 130 mph
V 240 km/h or 149 mph
W(ZR) 270 km/h or 168 mph
Y(ZR) 300 km/h or 186 mph
ZR Above 240 km/h or 149 mph
Car tyres: capabilities
You cannot compare performance between different sizes. So start with the size you're looking for and then consider what you want in terms of its capabilities.
Car tyres: grip
How well a tyre grips the road surface depends primarily on its rubber compound and the grooves that form the tread pattern. Remember, it's the tyre surface that's in direct contact with the road that does all the hard work.
In wet conditions, water lessens the contact between the tyre and the road, reducing grip. Taken to extremes, the result is aquaplaning - when there is no direct contact between rubber and road resulting in a loss of control. The tread grooves are designed to expel water from between the tyre and the road. Each manufacturer designs its own tread pattern to achieve this.
The more efficiently the grooves expel the water, the better the tyre will be at maintaining grip in wet conditions.
In dry conditions, the friction between tyre and road is the main factor in maintaining grip. If you brake harshly, accelerate rapidly or take a corner too fast, this tends to overcome the frictional forces, in which case the tyre will slip and tyre wear will be accelerated.
Car tyres: noise
Most tyre noise comes from the tread as it comes into contact with the road. So the hardness of the rubber, the shape of the tread and the squareness of the tyre's shoulders (the edges of the tread in contact with the road) influence the noise. The run flat tyres are bad at creating high level of noise.
Car tyres: rolling resistance
Rolling resistance affects your car's fuel economy. This can make a significant difference to fuel bills over the life of the tyres.Some tyres have words like 'fuel saver', 'eco' and 'energy' in their names, which imply low rolling resistance, but this isn't necessarily the case.
What makes up car tyres
Car tyres are a complex assembly of materials with very different properties. The following are some of the key elements:
The tread rubber compound determines how well the tyre grips dry roads. In the wet, the tread grooves disperse water, maintaining rubber contact and therefore grip.
These combine with the air in the tyre, to carry the load. Lower, stiffer sidewalls have lower lateral compliance, aiding handling. The outside of the sidewall is where you will find the tyre size and specification markings.
Rubber-wrapped bundles of steel wire give structural rigidity to the tyre and hold the tread flat to maintain good contact with the road.
Ultra-strong steel wires with extreme resistance to stretching hold the tyre onto the rim, even at very high speeds and when cornering.
Why the Correct Tyre Pressure Important?
Having the right tyre pressure can add ages onto the length of time that your tyres are deacent or road worthy. Not only that, but it also improves the overall safety of your vehicle and helps you use less fuel, so is good for both the environment and your bank balance, i thought you might take an interest now!
If you drive on tyres that are under inflated, they are prone to overheating. If they are over inflated they can cause you real problems steering and driving your car properly on the road, which could lead to an increased chance of a collision.
It's reported that around 5% of fatal accidents on the UKs roads are caused by under-inflated tyres suddenly failing, and it is such a problem that you could be fined £2,500 per tyre if they are over or under-inflated enough to be considered un-roadworthy.
So apart from the legal and safety aspects, there's also a good financial case for checking your tyre pressure. Over and under inflated tyres are more likely to be damaged than those that are inflated to the correct pressure. Either extreme can also lead to excess tyre wear: under-inflated tyres will wear down quicker along the walls of the tyre, whereas over-inflated tyres will cause wear around the centre of the tyre. This is likely to lead to early replacements and cost you more money.
Driving with the wrong tyre pressure can also make you use more petrol! This is because under-inflated tyres increase rolling resistance and your car needs to use more fuel to maintain the same speed as when your tyres have the correct pressure. So to sum it all up, you can save money, stay on the right side of the law, remain safe, and even reduce your ‘carbon footprint' just by making sure you have the correct tyre pressure. By having your tyres inflated properly you will, use less fuel and that means there's a good chance that your vehicle will produce less Co2 emissions! Now thats got to be good!