Checklist for buying new tyres

Beginning from this week, I wish to treat major areas of concern to guide you as you prepare for the Christmas celebrations. My first focus is on tyres, which are among the most important parts of a vehicle but unfortunately the least understood. Without tyres your vehicle is useless. You need tyres to start to […]

Beginning from this week, I wish to treat major areas of concern to guide you as you prepare for the Christmas celebrations. My first focus is on tyres, which are among the most important parts of a vehicle but unfortunately the least understood. Without tyres your vehicle is useless. You need tyres to start to move and stop the vehicle. So buying tyres is a task you need to undertake very carefully otherwise your safety and that of others could be put in grave danger.
However,you must guard against the blunder committed by a friend of mine who daily boasts that once he is assured of sound tyres,he is at liberty to clone the Formula 1 driving tendencies. Today he has repented from the foolish notion that having a brand new tyre or installing brand new tyres is a licence to drive excessively. Installing brand new tyres is no guarantee that you will avoid a road traffic crash; the only guarantee is responsible driving and deep trust in the protective hands of God Almighty.  
Before you buy any tyre,give serious consideration to (1) the size of the tyre; (2) the age of the tyre; (3) the physical condition of the tyre.
1. Tyre size
On the side wall of the tyres you will see figures like 215/75/15R, 195/65/14R and so on. These are designation for you your tyre sizes check your own tyres to know what is written on them. The first figure from the left is the width (from side wall to side wall) of the tyre in millimeters the middle number is what is known as aspect ratio used to calculate the height of side wall of the tyre. The last number is the rim diameter. When you go to buy tyres, you will mention all of these figures to the tyre seller so that he will give you exactly what you want.
There are various sizes of tyres in the market that can fit your type of vehicle but that doesn’t mean that those sizes are good/safe for your vehicle. Every vehicle has tyres specified by its manufacturers. If you check the tyre placard by the end of your driver’s door, hood or the vehicle manual, you will see the specification for your vehicle tyre sizes. Please stick to this specification while buying replacement tyres.
Don’t let the tyre seller give you something else. The manufacturers of your vehicle have taken a lot of safety factors into consideration before specifying your vehicle’s tyre sizes. If you change that, your vehicle may not handle well you may be risking a blowout and crash. Changing to fatter tyres as some people do may look better but not safer. In most cases, the manufacturers provide alternative sizes should you not find the original sizes the vehicle came with. The tyres placard will specify this alternative. However, there are some calculations you can make to get size apart from what the manufacturers specified that will give you the same result as the original specification but you need to know how to do the calculation. Otherwise stick to original specification.
2. Determining tyreage  
Even more important than the size of a tyre is its age. Unfortunately, most motorists as well as tyre sellers themselves don’t know how to check for tyre age. They depend only on visual inspection of the physical conditions. Some will invite a vulcanizer who will do a press-up (or is it press-down?) on the tyre to certify if it’s okay. What a wrong and dangerous thing to do.
Why the emphasis on the age of a tyre? Just as age could disqualify an otherwise promising marriage mate, age would disqualify a tyre even if every other thing seems alright from a visual inspection. Do not be deceived by the tyre’s looks. Every tyre has an effective life span beyond which you will be entering the danger zone. As a general rule any tyre more than 6 years old should be discarded. This rule, however applies to quality tyres with branded known names. Less quality tyres of course may not last that long; so how do you determine the age of a tyre? Unlike humans who can hide their age, every tyre provides information about its age but in a coded form.
Look at the side wall of your tyre and check for the letters DOT look around the DOT (to the left or to the right) until you get to either a 3-digit or 4-digit number boldly imprinted on the tyre without any alphabets attached to it. Some tyres though may not have the letters DOT printed on them. Just look around the side walls. You definitely will see a 3 or 4 digit number clearly imprinted on the tyre. The 3 or 4 digit number is the code designating the date of manufacture. Since it is a code, you need to decode it to get the age of the tyre. So let’s decode it. If it is a 3 digit number, check to see if it has a triangle sign attached to it. A 3 digit number without a triangle means the tyre was manufactured in the 1980s. The first two numbers from the left tell you the week in the year while the last number tells you the year in the 1980s. For example, if you have the number 341 (without a triangle), it means 34th week of 1981 (34 is the first two numbers from the left indicating the week while 1 is the last number indicating the year of the 1980s) if the 3 digit number has a triangle, it means the tyre was made in the 90s; so 341 with triangle means the tyre was made in the 34th week of 1991. If it is a 4 digit number it means the tyre was made any year from year 2000. For example, a tyre with 2302 means the 23rd week of 2002. The first two numbers from the left indicate the week while the last two numbers indicate the year. Four digit numbers do not have triangle signs.
From the date of manufacture you can now determine how old the tyre is. Do a simple calculation on tyre made in the 80s or 90s and see how old such a tyre could be. Even if a tyre looks brand new, don’t be deceived. Check the age; repeat check the age. If possible, find out for how long it has been left unused because the more unused a tyre is the more unsafe it becomes. Reason? See item 4 below. Please note that you start calculating the age of atyre from the date it was manufactured and not from the date you bought it.
3. Check for physical conditions  
After you are satisfied with the size and age, check for cuts, wears (either at the edge or the centre) bulges, swells, cracks, warp. This may be the time to do your press-up (or is it press-down) with the tyres. Any of these deformities could be a warning signal to stay off the tyre.
4. Spare tyre can be death trap
Given two tyres of the same age the one not in use (for a long time) is more dangerous than the one constantly in use. Surprised? Well that’s the way it is with tyres.For instance, if you bought two brand new tyres and kept one as spare and didn’t use it for say 12 months, the one in constant use is far safer than the one not in use. Why? When not in use, atmospheric gases have more damaging effects on tyres (whether brand new or not) not in use than those in use. Such gases harden unused tyres and make them brittle. When such tyres are eventually engaged, they could simply disintegrate and cause a crash.
A tyre that is in use counteracts the effects of the atmospheric gases as it roll and flexes. So if you have to engage spare tyres you have not used for a long time, drastically reduce your speed and change to a better tyre as soon as you can. From this you can see that those who park their vehicles for a long time may need to change the tyres when they eventually engage the vehicle again. It doesn’t matter even if you removed the tyres and stored them somewhere else. As long as they are affected by the air, you can be sure the damaging atmospheric gases will impact on them. SAFE DRIVING!