Performance Tyres


April 11, 2013 By Mike Lee
Last updated on July 27, 2015

Performance Tyres – a gripping read – Tyre choice is important, it is the only thing in contact with the road surface and therefore the most important component when it comes to the handling and stopping power of your car.

Low profile performance tyres can improve high speed stability, steering response and braking efficiency.

Tyre


Tyre Tech
We’re not going to go into how a tyre is made and its construction (how boring is that?). We will however explain what the important lettering and numbers mean.

The numbers that denote the size usually looks something like this –
205/45 R17 84Y

  • The first number (205) is the width across the tyre tread area and is measured in millimetres
  • The second number (45) is the profile (the height of the tyre wall). This is a percentage of the width, in this instance 45 percent of 205mm = 92.25mm
  • The following letter (R) denotes the tyre construction, in this case it’s a radial tyre
  • The third number (17) is the diameter of wheel for that tyre, measured in inches, so this tyre is for a 17” wheel
  • The last number (84) is the load index for each tyre, a lighter car will have a lower number, while a heavier car will require a higher number
  • The last character (Y) is the speed rating (see table below)

Other Markings
ECE type approval mark, which means the tyre conforms to the European Regulatory Authorities approval.

You may also see some of the following on the tyre: The manufacturer, tyre name (model if you like) construction type and details, country, load and pressure ratings, DOT reference (USA tyres (tires)) and of cause there will be a tyre wear indicator. There may also be a DOT reference with a four digit number showing the week (first 2 numbers) and the year of manufacture (last 2 numbers)

Tyre Speed Ratings

Speed Rating Miles/Hour Kilometers/Hour
N 87 140
P 93 150
Q 99 160
R 106 170
S 112 180
T 118 190
U 124 200
H 130 210
V 149 240
Z 150+ 240+
W 168 270
Y 186 300

 

Or Some Will Have

Speed Rating Miles/Hour Kilometers/Hour
VR 131+ 210+
ZR 149+ 240+
ZR+W 149-168 210-270
ZR+Y 149-186 240-300

 

Tyres Safety
Blowout2 Blowout

Don’t Mix Tyres

Don’t mix different types of tyres such as radial with cross-ply, also stick to the same tyre pattern all around. This is most important especially when braking in the wet, if you have more grip in the front than the rear or on one side than the other, it doesn’t take a genius to work out that your braking will be unstable. If you have a 4wd vehicle putting the same tyres on all 4 corners is most advisable, it’s possible to damage your transfer box if you don’t.

Cheap Tyres
Don’t bother with remoulds or retreads (it’s just not worth it on a performance car), part worn are ok, but you get what you pay for and you need to find the right one (with equal tread) to match your other tyres (see don’t mix your tyres above). New performance tyres from unknown brands – buy at your own risk, we say stick to the known and trusted, as they may look similar, but the compound of these cheap imported tyres are usually inferior.

Putting Them On
Usually if you have 2 new tyres fitted you should put them on the rear. As front tyres tend to wear out quicker (unless you have a heavy right foot and a RWD car!), we would generally dispence with the worn fronts and move the now part worn rears to the front. This is because demonstrations have shown that a loss of control at the rear from a skid or blowout etc is more difficult to correct than at the front and by having the best tyres placed at the rear will reduce this from occuring (of course this advice is based on you losing control in the first place and your level of driving skill, there are too many variables that can occur to alter this advice, but in general this is deemed the most appropriate for the masses). Also to note is that under braking, your cars weight is transferred to the front, which reduces weight at the rear, therefore (although it seems counterintuitive) the more tread on the back tyres the less that lack of weight will cause a loss in traction (hope that makes sense?). Don’t bypass getting your wheels balanced when putting new tyres on either.

Check Your Tyre Pressure
Incorrect tyre pressure can increase fuel consumption, tyre wear and rob horsepower. You should check your tyre pressure when the tyre is cold.

Check The Overall Tyre Condition (Regularly)
Worn Tyre
Check for nails, bumps, splits and uneven tyre wear (uneven tyre wear can mean either the suspension geometry is out, the wheel alignment is out, or the tyres have incorrect pressure) – (or for those boy racers out there, you go round the corner too damn quickly too often!). Poor condition tyres can cause blowouts. Tyres can also deteriorate with age and have been known to blowout and shred themselve due to their age. We would also recommended that you have a wheel alignment (tracking) carried out every time you get new tyres fitted.

Worn Tyre Tracking Out
Almost Certainly Due To The Tracking Being Out.
(see our suspension guide)

Tyre Tread Depth
Tread Amount
There is a legal minimum amount of tread depth required on a tyre of 1.6mm in the UK. 75% (3 quarters) of the breadth of the tyre, around the entire circumference must have this minimum tread depth. All tyres have a tread wear indicator to help judge this. It is also recognised by some that even 1.6mm is still too little. There are high fines for not complying.

Tyre Blow Out Advice


Aftermarket Performance Tyres
Performance Tyres Performance Tyres
Basically, lower profile performance tyres with a stiffer side wall and a softer compound will improve your cars handling, high speed stability, steering response and braking efficiency (depending on the road surface – can be less stable on uneven surfaces and bad weather). Also be aware that it is the tyres that cushion the unsprung weight (weight of the tyres, wheels, brakes and a percentage of the weight of the suspension components).

Lower Profile
Low-Profile-Tyre
By lowering the profile you are reducing the amount of flex in the tyre wall, keeping the tyre more planted with less roll. The use of softer compounds also gives better grip adhesion on the roads surface.

Performance tyres come in all types of rubber compounds and patterns, their softer compounds will increase road adhesion. However some will be better in the dry and others better in the wet. It’s important to consider when and for what you are purchasing your tyres for. There’s no point in buying a tyre designed for high performance in the dry if the cars a daily driver, you’ll just regret it when you lose your car in the wet.

Package Deals
Wheels And Tyres
Combining wheels and tyres may save you some money, there are many companies out there selling wheel and tyre packages just for your car.


Things to watch out for when purchasing your performance tyres

  • Your Insurance can be void if you select the incorrect tyre for your car/application
  • You may consume more fuel consumption, due to increased contact and adhesion
  • Softer compound performance tyres wear out quicker, of course your driving style will have an effect on tyre wear also
  • Most lower profile performance tyres will not allow for puncture repairs due to the minimum sidewall height required to affix the repair pad. Therefore you may have to replace what could otherwise be a perfectly good tyre
  • Getting larger wheels with low profile tyres that step on the inside of the rim, will increase your chances of curb damage

 


Our Recommendations
As always, when it comes to something that affects safety, we recommend you seek professional advice for your particular car or application. Stick with known brands and don’t get carried away. Remember your brakes may stop the wheels from rotating, but it’s your tyres that stop the car from moving!


Silly Tyre Advert

Big Tyre
Wow! – a set of 4 please!