Because I wanted to know the truth of this. Most of the tires I bought had these dots and never paid attention to it. I did not believe it had anything to do with quality check + I saw some comments that led me to find out more about this. Thanks for the info. btw
It has no reflection on the
quality of the tyre. The
quality is primarily the Grip, Durability & the Rolling Resistance of the product. Not how many metal pieces are required to balance it.
The quality primarily depends on
who and where it's manufactured. But no manufacturer can make a
perfect tyre and thus there will be dots.
Also tyres do not necessarily expire in 5 years. Under storage it mainly depends on the t
emperature and UV light (both Sun & artificial), ozone exposure, humidity, and deformation.
However, in Britain, from 1st February 2021 it was made be illegal to use tyres more than 10 years old on the front steered axles of heavy goods vehicles, buses and coaches. The ban will also apply to any wheel in a single configuration on a minibus. They also recommend that recommend that new tyres that have not been used for six years or more should not be fitted to vehicles.
Michelin warranty is usually six years. Michelin tested tyres
stored & unused for 10 years and found there's only negligible difference between these and a tyre that's one year old . However, tyres that were stored for 20 years at a constant 40 deg C to simulate running for 40,000 kms deteriorated (tyre material) faster than a one stored under proper conditions. They also claim that the performance between a tyre that was newly made and one that had been stored for three years is the same. Even so, Michelin does agree with the BTMA’s standpoint that tyres that are 10 years or older from the date of manufacture must be replaced or disposed of.
More details can be found on the sites of popular tyre manufacturers , the US DOT. NHTSA and the BRMA sites. I wouldn't be worrying at all on dots.