grober
MB Master
Interesting little video clip on tyre tread depth on the autoexpress site. http://www.autoexpress.co.uk/ Evidently 3mm is minimum tread depth for decent grip in wet conditions. watch the video and make your own mind up.
Brian WH
MB Enthusiast
Very interesting and even more reason why I changed my tyres recently, despite forum members saying I shouldn't have done.
Satch
MB Enthusiast
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Glad to see Auto Express at the top of their game again with an "exclusive"
RESEARCH INTO WET DRIVING CONDITIONS CALLS FOR TYRES TO BE CHANGED AT 3MM
Independent research undertaken by MIRA reveals that braking distance deteriorates in wet conditions when tyre tread depth drops below 3mm.
Although the legal tread depth limit is 1.6mm, a threshold set by motoring experts some 30 years ago, Roadsafe says there is now compelling evidence that motorists should check and change their tyres at 3mm. Road accidents where wet conditions are a contributory factor are on the increase.
It’s a well known fact that in wet conditions braking distances increase. Thirty three of all road accidents already occur during the summer months and with heavy downpours and flash floods becoming a permanent fixture of an English summer (in 2004 average summer rainfall increased to 314.9mm3), there is every possibility this figure could rise over successive years.”
The trend is already upwards according to Town and Country Assistance who state that road accidents where wet conditions are cited as a major cause have increased from 1 in 12 in 1998-99 to 1 in 4 in 2003-04.
“There has been a long-standing belief within the motoring industry that wet weather tyre performance deteriorates as the tread depth wears away. A comprehensive test of different vehicles and tread depths now scientifically proves and backs up these claims,” says MIRA’s project engineer, Simon Aldworth, who carried out the research into tyre tread performance at the organisation’s headquarters in Nuneaton.
MIRA’s research was carried out on four separate vehicles, a mid range family hatchback, an MPV, executive saloon and a high performance saloon car, measuring stopping distances at 50 mph in conditions that represented simulated moderately heavy rain (0.5mm to 1.5mm water depth). The research discovered that tyres with a 3mm tread had a 25% better performance than those at 1.6mm. In terms of stopping distance this represents an extra 25 feet in wet conditions. In one test, compared to an 8mm tread the stopping distance on a tyre tread depth of 1.6mm was 13 metres (42.25ft) – the equivalent to double the length of a typical living room.
We are not suggesting that 1.6 mm tyre tread depth is not safe, However with 300,000 road accidents taking place every year and a climate which is now much more susceptible to heavy rain, particularly in the summer months, there is need to take action now. If motorists replaced their tyres much sooner stopping distances would improve, accidents reduce and lives would be saved.
Major car manufacturers also recommend changing at 3mm, and they specify in their owner manuals that tyre performance and safety margins decrease once the tread depth reaches 3mm.
RoSPA is advising motorists of a four point tyre health check to help increase driver safety:
• Every two weeks check the pressure of your tyres when they are cold.
• Check the tread depth of your tyres. Although the minimum legal UK tread depth is 1.6mm, RoSPA recommends that tyres should be replaced when the tread depth reaches 3mm. As the depth decreases stopping distance in wet weather will increase. This is more notable on cars with larger wheels and wider tyres.
• Check tyres for damage. Look out for any cuts, cracks or bulges as these can lead to slow punctures and blowouts.
• Finally, don’t forget to check the pressure and tread depth of your spare tyre.
http://www.rospa.com/roadsafety/advice/motorvehicles/tread_depth.htm
RESEARCH INTO WET DRIVING CONDITIONS CALLS FOR TYRES TO BE CHANGED AT 3MM
Independent research undertaken by MIRA reveals that braking distance deteriorates in wet conditions when tyre tread depth drops below 3mm.
Although the legal tread depth limit is 1.6mm, a threshold set by motoring experts some 30 years ago, Roadsafe says there is now compelling evidence that motorists should check and change their tyres at 3mm. Road accidents where wet conditions are a contributory factor are on the increase.
It’s a well known fact that in wet conditions braking distances increase. Thirty three of all road accidents already occur during the summer months and with heavy downpours and flash floods becoming a permanent fixture of an English summer (in 2004 average summer rainfall increased to 314.9mm3), there is every possibility this figure could rise over successive years.”
The trend is already upwards according to Town and Country Assistance who state that road accidents where wet conditions are cited as a major cause have increased from 1 in 12 in 1998-99 to 1 in 4 in 2003-04.
“There has been a long-standing belief within the motoring industry that wet weather tyre performance deteriorates as the tread depth wears away. A comprehensive test of different vehicles and tread depths now scientifically proves and backs up these claims,” says MIRA’s project engineer, Simon Aldworth, who carried out the research into tyre tread performance at the organisation’s headquarters in Nuneaton.
MIRA’s research was carried out on four separate vehicles, a mid range family hatchback, an MPV, executive saloon and a high performance saloon car, measuring stopping distances at 50 mph in conditions that represented simulated moderately heavy rain (0.5mm to 1.5mm water depth). The research discovered that tyres with a 3mm tread had a 25% better performance than those at 1.6mm. In terms of stopping distance this represents an extra 25 feet in wet conditions. In one test, compared to an 8mm tread the stopping distance on a tyre tread depth of 1.6mm was 13 metres (42.25ft) – the equivalent to double the length of a typical living room.
We are not suggesting that 1.6 mm tyre tread depth is not safe, However with 300,000 road accidents taking place every year and a climate which is now much more susceptible to heavy rain, particularly in the summer months, there is need to take action now. If motorists replaced their tyres much sooner stopping distances would improve, accidents reduce and lives would be saved.
Major car manufacturers also recommend changing at 3mm, and they specify in their owner manuals that tyre performance and safety margins decrease once the tread depth reaches 3mm.
RoSPA is advising motorists of a four point tyre health check to help increase driver safety:
• Every two weeks check the pressure of your tyres when they are cold.
• Check the tread depth of your tyres. Although the minimum legal UK tread depth is 1.6mm, RoSPA recommends that tyres should be replaced when the tread depth reaches 3mm. As the depth decreases stopping distance in wet weather will increase. This is more notable on cars with larger wheels and wider tyres.
• Check tyres for damage. Look out for any cuts, cracks or bulges as these can lead to slow punctures and blowouts.
• Finally, don’t forget to check the pressure and tread depth of your spare tyre.
http://www.rospa.com/roadsafety/advice/motorvehicles/tread_depth.htm
...and AGE of the spare.Satch said:
I love it when an old car is for sale and the ad says "unused spare!". It's right up there with "contains original first-aid kit!" Guess what? They expire after about 3 years anyway...
low tread depth also materially and adversely affects quality of the ride, handling and noise levels.
when I put on 2 new rear tyres recently, it transformed the car .. I had not noticed the gradual deterioration until 1 day it struck me that the car was feeling a bit 'worn out'
when I put on 2 new rear tyres recently, it transformed the car .. I had not noticed the gradual deterioration until 1 day it struck me that the car was feeling a bit 'worn out'
fred_raven
Active Member
definately worrying - will be keeping a much closer watch on mine from now on 
You're not 100% correct there, the handling of my car is great with the front centres at about 2mm! Steering is sharp and precise, the tyres are quieter and I feel every tiny bump and piece of grit because the rubber doesn't absorbe it.C240Sport97 said:
Sadly I have to replace them. The rears are still good though, they'll prolly end up back on the front again...
perhaps you have a different driving style to me ...
Shude said:
Not to sure whether all they have shown is that you should drive slower in adverse conditions. I would suspect that the same test carried out with 7mm of tread against 3mm would show similar results. With that much water falling onto the road, visibility would be an issue and should slow the traffic down. Having said that, I will consider changing my tyres a little earlier. Can't have the canvas showing again
