The official line is "All tyres have a life span and a date stamp on the sidewall showing the week and the year it was manufactured. So 2206 means the tyre was made in the 22nd week of 2006. You should never use tyres over five years old whether or not the tyre is being used, as the rubber in a tyre degrades over time."Mike and his Macan wrote: ↑Fri Nov 17, 2017 10:29 pm Great advice, on tyres I agree that there are so many variables when it comes to tyre wear ... basically it’s not a science .. one point I would make is always when renewing tyre try and get the newest date stamp, as this will make a difference to the traction..but in my opinion will wear quicker that older ones as the silca tends to harden over time.
This is particularly relevant to high performance cars / SUVs.
On trailers, caravans, motor homes and older collectors' cars then do not fit new tyres that are already 5 years or older. All road tyres to be removed after 10 years of age regardless.
Gradings on the the tyre sidewall also show values for:
tread wear
traction
temperature
A control tyre is assigned a grade of 100. Other tyres are compared to the control tyre. For example, a tyre grade of 200 should wear twice as long as the control tyre.
Of current tyres:
15% are rated below 200
25% are rated 201 – 300
32% are rated 301 – 400
20% are rated 401 – 500
6% are rated 501 – 600
2% are rated above 600
The treadwear grade is a comparative rating based on the wear rate of the tyre when tested under controlled conditions on a specified government test track. ... As a result in real world driving, it would be incorrect to say that a tyre with a treadwear grade of 200 gets twice the life of the Course Monitoring Tyre.
Enough already I hear you scream!