Decoding the numbers of your car's tyres can tell you all sorts of things
TYRES ARE ROUND and black, right? Well, yes, but a tyre also comes with a number of markings that reveal all sorts of information to the trained eye, from how much weight it can carry to the maximum speed it can be safely driven to (not something you want to find out on the open road).
One of the most important things for a consumer to know is how old a tyre really is. That’s because a tyre’s compound can degrade with time from lack of use — rolling a tyre actually ‘stirs’ some of the chemicals in the compound, and the rubber tends to harden and crack without this regular mixing.
To read a tyre’s age, simply look for the DOT code. It stands for "Department Of Transportation", a US governing body. Starting with "DOT", the code has a string of numbers and letters that signify its place of manufacture, and the last four digits are what you’re looking for: they tell you the week of production, followed by the year.
So "2114" tells you that a tyre was manufacture in the 21st week (the "21" part tells you that) of 2014 (the "14" part).
It’s important to know the manufacture date because tyre manufacturers offer warranties that start from when a tyre was made, not when it was sold.
Of course, some tyre retailers go one better and guarantee a tyre from the date it was sold, along with other benefits.
The Drive-in Tyre Shop at Cycle & Carriage, for example, offers a five-year warranty from the date of purchase. That’s a sign of a commitment to selling only fresh stock.
The venue also offers nitrogen gas filling, tyre patching, tyre rotation, tyre valve replacement and wheel balancing.
The technicians there can even conduct a safety check in case you have doubts about the condition of your tyres. Tyre markings may tell you a lot, but trained eyes can look beyond them and see much more.