Here's a quote from National Tyres website;
The law requires car tyres to have a minimum tread depth of 1.6mm in a continuous band around the central three quarters of the tyre. To help you judge how much tread you have on your car tyres, manufacturers often mould tread bars at roughly 1.6mm.
If you can see these bars your tyres are about to become illegal and unsafe. However, for optimum safety, most manufacturers recommend that your tyres are changed at 3mm.
Many manufacturers now include a Tread Wear Indicator (TWI) within the grooves of the tyre tread which become more visible as the tyre wears down. Whilst these markings are an indicator, always check the tread depth using a tread depth gauge and check your tyres regularly for bulges or wear.
I think MOT inspectors start getting 'nervious' at 2.0mm and usually trigger an 'advisory.' If the MOT station also does tyres and exhausts they will be on to that as quick as a flash.
It does raise an interesting question though.
A friend of mine runs a lease M/B Vito van for his deliveries. He changes to cold weather tyres in the winter because that's part of his business' health and safety with regard to his employees.
I've never bothered as I don't normally venture out when the roads and icy and slippery. But he did make a valid point. We had a bad winter in 2011/12 in the North East. His father got stuck on a hill in the snow with his 4 x 4 VW Tiguan with summer tyres on. His son pulled him up it with his front wheel drive Vito with winter tyres on.
I looked into winter tyres a few years back after a near miss, problem is while they're are safer on icy slippery roads they are
less safe than non winter tyres in normal or even wet conditions, your friend is actually putting him/herself and employees in a less safe position by using them all winter.
using winter tyres in winter is less safe than summer tyres in winter? one of the dumbest comments I have read on this forum,
to the OP, yes you are asking a dumb question, seriously if you cannot open your eyes and look at your tyres to see how much tread is on them then no one on the internet is going to be able to help you when you cant even help yourself, take the van to a tyre garage and ask them on there opinion
If you look at the manufacturers test results, he's actually made a valid point Scrimble.
The manufacturers have to test both summer and winter tyres at 25 degrees C. Winter tyres don't perform as well as summer tyres at that temperature. They should leave the standard for testing summer tyres at 25 degrees and winter tyres at say 5 degrees; then we will get a more realistic performance result.
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The testing process that tyres have to go through for their tyre labelling values is standardised, and with good reason. In order to have consistent results across brands this needs to be the case. However the testing across different types of tyre is also standardised, so summer tyres, all-season and winter tyres are all tested in the same way. This standardisation states that all tests should be carried out at 25 degrees Celsius! So a cold weather tyre that is designed to offer superior performance in colder conditions has to be tested in a temperature range outside of what it has been designed to perform at. The rubber polymers that make up a winter tyre are designed to ‘work’ (be that stay supple in the cold to offer short braking distances, superior grip…) at temperatures below 7 degrees, therefore the labelling results from a test at 25 degrees don’t say anything at all about their actual cold weather credentials.
Winter tyre manufacturers will happily admit that their products won’t perform quite as well as their summer counterparts in warmer conditions, because this is not what they are designed to do. If the tyre manufacturers were allowed to test their winter tyres in more suitable conditions (less than 7 degrees) then the results would be very different indeed. Tyre labels were designed to offer the consumer more information on the products they are looking to buy but for winter tyres they just increase confusion, well done the EU! To be honest I (the writer of this article) have issues with tyre labelling even for summer tyres. I promise you, winter tyres perform best when it cold. The problem comes when you still have winter tyres on and we get a warm day.
For me, I don't believe that, living on the North East coast, we would benefit all that much for using winter tyres. But if I was living in the Pennines for example I would then seriously consider using winter tyres.