Tyre depth and why you should change at 3mm

At present, the UK law states that car & light commercial tyres should have a minimum of 1.6mm of tread depth in a continuous band around the central 3/4 of the tyre. (Just for perspective, the average thumb nail is about 1mm thick!)

One of the biggest issues with a tyre having just 1.6mm of tread depth left is the amount of water it can disperse and the subsequent stopping distance. Below 3mm the stopping distance for a car will greatly increase, at 1.6mm the stopping distance can be up to 44 meters longer (about 10 car lengths) than a similar car with a minimum of 3mm of tread remaining. That 44 meters (or 144 feet and a bit if you use old money) could be the difference between suffering a nasty incident - and avoiding one.

Cost vs Safety - it's Your Call!?

A recent survey of 100 random cars found that 67 vehicles had at least 1 tyre below the recommended 3mm limit.

Obviously replacing your tyres at 3mm instead of the very minmum 1.6mm will cost you a little more - but "how much more?" we hear you cry!
Well... taking the averages into account, it's broadly £20 a year more, now divide that by 52 weeks and it comes to just under 39p a week. Not a lot really, is it?

If you take further into account your insurance excess and potential premium increase if you do suffer an avoidable incident then 39p a week should be seen as a bit of a bargain.

It could also be said that the minimum depth should be even higher...A study by MIRA back in 2003 highlighted that 3mm was the critical depth at which the level of grip and performance massively reduces.

Take the 20p test on your tyres! If you can see the edge, it's time to change!

Most drivers don't really appreciate the absolute importance of good tread depth. It's not until that moment when you're skidding towards a car in front of you that you really tend to appreciate what your tyres are doing for you and how they can keep you safe. The reality is that every time you brake with good tread depth, you're avoiding this very situation!

Braking distances is not the only thing that is affected by tread depth. We mentioned water dispersal earlier... The risk of aquaplaning is greatly increased the lower the tread depth. The deeper the grooves, the more water can be channelled through and away from the tyre.

Already convinced? Click to get safe now!!

The 1.6mm Tread Depth Law

So... why are we stuck at 1.6mm? It actually dates back to 1992 when cars had somewhat slimmer tyres! The tread depth law before 1992 was actually just 1mm. Since then though, tyres have got much wider! This means you have a larger contact patch with the road. Great when it's dry as more contact equals more grip! But when it's wet, wider tyres take far less lying water to cause the effect of aquaplaning (think of it as a thin tyre cutting through the water, and a wide tyre sitting on top of it!)

Another question... why don't they just change the law? Well it's currently not that simple. The 1.6mm minimum tread depth for car tyres is set across the EU by a European directive and at the moment there are no plans to change this.

Although times are obviously changing...

So are the rest of the Europeans happy with the 1.6mm minimun directive?

The TUV (the German equivalent to our Transport Research Lab - or TRL for short) would like to increase the limit to at least 2.5mm. The German motorist is generally a more cautious driver and change there tyres before they get to 1.6mm, one of the downsides of this is that the old tyres are then shipped to the UK to be sold as part worn tyres with all the inherent problems you get with second hand tyres.

So until the Eurocrats decide that the rules need to be changed we will be stuck with a legal minimum of 1.6mm and a recommendation of 3mm, it is your life and only you can decide what it is worth.

If you want more information or to book in to have your tyres changed, call us today on 0333 444 5454 or visit our homepage by clicking here, enter your tyre details/postcode and stay safe on the roads!