All relevant information on tyres are displayed on the sidewalls, these include date of manufacture, tyre size, inflatable limits, treadwear, traction, temperature resistance, load and speed capacities.
Date of Manufacture
Tire expiry is four years from the date of manufacture. Use of expired tyres may result in tire burst, especially when the weather is hot. Check for a stamp displaying the date of manufacture on the side wall of your tyre, it is four numbers for example (*2214*). The first two numbers represent the week of the year the tyre was made. There are 52 weeks in a year, this means the tyre was made in the 22nd week of the year while the last two numbers indicate that the year of manufacture is 2014. Following series of fatal accidents occasioned by tyre bursts, the Lagos State Government has started the enforcement of compliance with tyre manufacture dates. A note of warning: Please buy your tyres from trusted sources because unscrupulous tyre dealers can re-stamp and alter the date of manufacture on tyre to show a more recent date.
TYRE SIZE
Your car manufacturer has recommended the best rim and tyre sizes for your car to achieve maximum driveability, handling and safety. This is often on a label by the driver side door or the frame. Some manufacturers may display only a single choice, while others may state alternatives as well. The numbers are written in the following format 255/55/R18 on the label. When you buy a new tyre make sure it’s same size as recommended. The first number is in hundreds i.e 185 or 255 or as the case may be, such numbers represent the width of your tyre in millimetres from one edge to the other, the second number 55 or 60 or as the case may be represents the ratio of height to width, while the R18 or R13 or otherwise indicates the rim diameter.
TYRE PRESSURE
Use the right inflation pressure recommended for your tyres at all times, do not under inflate or over inflate tyres. Michelin posits that a tyre which is 20% under- inflated can give 20% less mileage. Over-inflated tyres can get overheated, use more fuel and wear out faster. Some modern cars now come with sensors that notify you of low pressure on any of your tyres including the extra tyre. Recommended tyre pressure can be found pasted on the door side or the door frame post of cars. Everyone using a car should learn how to check tire pressure with pocket tire pressure reader available in shops. Check your tyre pressure regularly within an average of two weeks to one month.
Temperature Resistance
The temperature symbols are inscribed on the sidewall of tyres in alphabetic symbols of ‘A’ or ‘B’ or ‘C’ with ‘A’ symbolising hot area, ‘B’ symbolising Normal weather and ‘C’ symbolising cold area. The letters indicate your tyres resistant to heat. DO not use a tyre graded as ‘C’ in Nigeria, it can get heated up and burst.
Treadwear Number
This number shows the tyre’s wear rate. The higher the number is, the longer it should take for the tread to wear down. For example, a tyre graded 400 should last double the life of a tyre graded 200.
Traction
This indicates the ability of a tyre to stop on wet pavement. The higher the traction grad of the tyre the greater the ability to stop your car on wet roads at a shorter distance. Traction is graded from highest to lowest as “AA”,”A”, “B”, and “C”.
Max. Load Capacity & Tyre Speed Symbol
The load rating of your tyre is inscribed on the sidewall, just to the right of the diameter. Both load capacity and speed are written together. A tyre with a load and speed index of 91V can carry 615kg of weight at a maximum of 240 kilometres per hour. The number, 91 indicates the max. load that can be carried by the tyre. Symbol ‘V’ indicates the maximum speed at which a tyre is designed to be driven for extended periods of time on the maximum load. Examples, ‘Q’ up to 160 km/h, ‘R’ up to 170 km/h, ‘S’ up to 180 km/h, ‘T’ up to 190 km/h, ‘U’ up to 200 km/h, ‘H’ up to 210 km/h, ‘V’ up to 240 km/h, ‘W’ up to 270 km/h, ‘Y’ up to 300 km/h, ‘Z’ above 300 km/h.
