KNOW YOUR TYRES

This is where we try and explain some of your tyre related queries.

What do those numbers and letters on the side of my tyres mean?
What is Balancing and what does it mean for my tyres?
Why do my tyres wear out so fast?
I was told my Tracking was out, what does this mean?
I heard that tyres can be repaired, is this true?
How do I take care of my Alloys?

Tyre Sizes & Speed Ratings

A tyre marked 155/80R13 78T relates to the following.

155 - 'Nominal' (i.e. not exact) this is the width across the tread in mm.
/80 -This is the aspect ratio. 80% of the tread width is the side wall height
R - Is the construction of the tyre. In most cases R = Radial
13 - Is the rim diameter in inches.
78- Related to a load index chart of what weight the tyre can carry.
T - Is the speed rating.

The speed rating relates to a speed that the tyre can with stand when run on a test track. The speeds are as follows;

speed symbol	T	H	V	ZR	W	Y
speed mph	118	130	149	see note	168	187

Now no one really drives at these speeds everyday but it doesn't just mean top speeds. It is better to think of it as a torque rating that will match the size and power of your engine. For instance if you put your foot down after the traffic lights the only contact point your engine has with the road is your tyres. They need to be of a construction designed to deal with those types of acceleration.

Note: ZR rated was unlimited in its top speed, to correct this noncom most tyres under ZR are now dual marked W or Y, Dunlop still do a few tyres marked solely ZR.

A correctly balanced car can reduce the cost of motoring

An incorrectly balanced car can cause greater tyre wear, higher fuel costs and increased repair bills. You should also note that there is also a small increased safety risk to incorrectly balanced tyres.

So what is balancing? (these are the basics)

Your rims and tyres no matter how good quality will still have a small amount of imbalance due to manufacturing tolerances causing your wheels to unnecessarily vibrate at speed.

A mere 10grams imbalance will cause 3.8kg centrifugal force at 150km/h- 93.2mph. At today's speeds this can cause vehicles to become a hazard as the steering vibrates, braking is affected and wheel bearings, suspension and axles are exposed to unnecessary stresses.

An out of balance wheel means the tyre takes more punishment. This can shorten it's life and cause excessive and uneven wear of the tread.

The extra effort required to rotate an out of balance wheel means your car becomes less economical to run.

Tyre care and wear

If you keep an eye on your tyres they will go a lot further. Spot the problem early and it can be rectified.

How does the tyre wear?

Evenly across the tread
Then your tyres are fine just check for any major cuts or bald spots.
If the centre of the tyre is wearing quicker than the rest
This suggests the tyre is over inflated. Refer to your hand book or pop in for a free pressure adjustment.
If BOTH the outer edges of the SAME tyre are wearing quicker than the rest
This suggests the tyre is under inflated. Refer to your hand book or pop in for a free pressure adjustment.
If only the inner edges of BOTH the tyres (on same axle) are wearing quicker than the rest
This suggests the tracking is out.
If only the outer edges of BOTH the tyres (on same axle) are wearing quicker than the rest
This suggests the tracking is out.

Tracking and Alignment

Tracking can be a complex issue and takes into account a lot of different parts of your vehicle.

At TREADS we cater for the most common tracking that's required which is called toe (toe in or toe out).

If you would like any help or advice then give Phil or Nathan a call (01803 317 304) or pop in for a check.

Puncture Repairs

At Treads we also undertake puncture repairs of various natures.

A simple nail or screw in the tread can be repaired on site in a short space of time. If the screw has entered outside of the safe repairable area which is roughly the central 75% area of the tread then it maybe a major repair. Any major repairs like side wall damage, has to be inspected first and then sent to an authorised repair agent.

Let Treads take care of your Alloys

The weights used to balance your alloy's are going to be spending a few thousand miles being very close to each other. It is therefore critical to get the right weight for your wheel, to ensure a correct fit.

Alloy wheel care Make sure these are coated. We always use coated weights which prevents contact corrosion between wheel and weight. A corroded weight when removed will pull off the finish and expose the corroded metal, making your alloy's unattractive and considerably reducing there value.

At Treads Tyres we stock the original equipment weights (weights put on when the car was made by the manufacturer) for BMW, Jag, Nissan, Toyota, Mercedes, Volkswagen, Audi, and French alloys. We also stock coated weights and hidden stick on weights.