Safe Minimum Tyre Tread Level?

c-m

If it was particularly unsafe before the legal minimum then the legal minimum would be set higher.

If they are close the minimum, change them. If not then leave it.

Tread is only there to clear water. You actually have more grip the more rubber you have on the ground, so a slick tyre is likely gripper than a treaded tyre in dry conditions.

In the wet you risk aquaplaning if you have insufficient tread.

bigjl

Personally when it is my money and tyres I replace as soon as I have the money, but have no issue with tyres approaching the 1.6mm level if it is summer and dry, if it was winter then i would change them at 2mm.

It is a personal and also fiscal decision though the London Ambulance Service has a policy of changing them at 2mm, I believe a lot of Police forces have similar limits, though wouldn't be surprised if Traffic Police would rather they werwe changed at 3mm.

Note that Germany has a limit a lot stricter than the UK, I am sure it is 3mm or maybe 4mm, as most used tyres in the UK come from germany and other European countries with stricter limits.

Incidentely the tyres on my Mondeo where on 3 mm all round when I had it MOT'd in July, I have now done another 11k and they are still at 2mm, these tyres are Toyo Proxes and not a hard wearing Michelin, but I rarely get up any kind of speed, just school run and the odd run of 10 miles on dual carraigeways and motorways.

I did however rotate them this time so they are all on 2mm, so will need a complete set in a month or so.

TiTheRev

NeverAgain wrote: »

This raises another question - on which axle do you fit the new ones?

Many people say the new tyres should go on the back, but others say it doesn't matter.

Surely all the grip needs to be at the front? When a car brakes the weight is distributed to the front of the car and if the front tyres are newer then the grip would be better, likewise for turning, as you would need more grip at the front because the rears just follow the fronts!?

I've always put new on the front if I've only done 2.

NeverAgain_2

...surely all the grip needs to be at the front?...

Not according to Tyresafe.org.

Quoting: "However, recent demonstrations have indicated that it is more beneficial to fit the new rubber to the rear wheels, regardless of whether the vehicle is front or rear wheel drive."

http://www.tyresafe.org/news-and-events/detail/motorists-get-their-tyres--back-to-front--/

But as I say, opinions vary.

colino

Have you noticed a difference in handling? Unfortunately your question isn't possible to give a straightforward answer. The legal limit exists as an absolute threshhold to prevent people doing themselves harm even if they are car clueless. However, depending on the car/tyre combination and how and where you drive will set what is really acceptable. Good Michelins on a lightly driven, small hatchback seem to last forever. Goodyears are great initially on a performance/luxury car but will have you spinning on roundabouts when they get near 3mm.

Wh05apk

NeverAgain wrote: »

...surely all the grip needs to be at the front?...

Not according to Tyresafe.org.

Quoting: "However, recent demonstrations have indicated that it is more beneficial to fit the new rubber to the rear wheels, regardless of whether the vehicle is front or rear wheel drive."

http://www.tyresafe.org/news-and-events/detail/motorists-get-their-tyres--back-to-front--/

But as I say, opinions vary.

If fitting 2 then should be on rear, poor fronts will cause you to understeer, which is generally viewed as "safe", poor rears could cause oversteer, which is far more difficult for most people to control.

macman

My rears still have 5mm. I'm going for two new Bridgestones on the front via black circles, thanks to all for the advice.

Mr_K

For safety I was always told new tyres should go on the back; if you're more interested in performance put them on the front. I think the argument is that at least with the front you have some control with steering (ie. steer into a skid). If your back skids you've no control.

bigjl

The research was performed by Michelin and is directed at drivers that are on the lower end of the skill scale. It is a typical bit of the nanny approach to life that everybody has these days.

I have always replaced the driven axles tyres first and never had a problem with crashing due to different grip levels caused by new tyres.

The emergency services don't do this, they just change them as they need changed, though always as a matched pair. If the rears are worn then normally they will put the new ones on the front and the old fronts on the back.

Don't forget that when you rotate your tyres (specifically in the case of a FWD car) to even out the wear you are putting the less worn tyres on the front. And as this has been common practice for many people for years without any problem then it shows how flawed this research really is.


Personally the risk is higher that you will aquaplane or be unable to stop in an emergency due to the reduced grip at the front than oversteer due to new tyres on the front.

If you hammer into any corner in a FWD car and lift off mid corner you are going to oversteer anyway, having newer tyres on the back will make little if any difference, and yes I have read the report, and I don't agree with it.

However if we are talking about a RWD car then I would personally put the new tyres on the rear, but this report by Michelin was directed more towards FWD cars.

If you are unable to accurately assess the amount of grip you have under you then I suggest driving slower, as this will be much more beneficial.

johnnyroper

the reason it is recommended to fit new on rear is basically because we live in a nanny state.

if the more worn tyres are on the front the driver is more likely to feel the reduced grip through steering or spin on the power.
if worn are on rear driver will not really notice reduced grip until the back kicks out and it is too late.

personally i have new ones fitted to fronts if just having a pair fitted.