Tyre tread depth

[philameena]

What's the tread depth on a tyre when new and what's the legal minimum?

Just got the service report after the 10K service and the treads are listed as 6mm

 

[Johnsey]

1.6mm i think is the legal limit, there are normally wear indicators in the tread to show when you're on the limit

 

[BoyBrian]

New tyre depths usually 8 - 10 mm. Legal limit is 1.6mm across the centre 75% (Three Quarters) of the tyre.

 

[jamesb]

The Pirelli P Zeros on my LCR were 8mm in the centre two bands and 7.25mm in the two outer ones when new.

I think 1.6mm average across three quarters of the tread is legal min.

 

[rayko]

The clearest description I have found is here.

"A minimum of 1.6mm in a continuous band throughout the central three-quarters of the tread width, throughout the whole of the circumference."

http://www.etyres.co.uk/uk-tyre-law

 

[WeeJase]

tread wear indicators are normally set above the limit by a mm or so yes?

 

[Deleted member 7659]

Anything less than 3mm has significant influence on stopping difference, esp in wet. That's the German limit, I believe hence lots of part worns come to the UK with 3-4mm tread.

Adrian

 

[Johnsey]

tread wear indicators are normally set above the limit by a mm or so yes?

I thought they were the limit

 

[philameena]

thanks all

 

[Martinoutfront]

When you start to get close on the fronts, keep an eye on the inside passenger tyre, as on my LCR it was wearing a lot more than the rest of the tyre and you can only spot it you put the car on full lock.

 

[LeonR]

Couldn't care less about the fronts but 2.5 is the absolute minimum for save driving during rainfall. By the way the rears are far more important on a front wheel drive car (the best tyres always have the be at the rear). Beware that some leons wear different on the in and outside (especially lowered), recently saw a leon with 5 on the outer and no profile on the inner tyre!

 

[chiefsilverback]

Couldn't care less about the fronts but 2.5 is the absolute minimum for save driving during rainfall. By the way the rears are far more important on a front wheel drive car (the best tyres always have the be at the rear).

How do you work that out? Given that the front tyres are used to transfer all of the car's power to the road, steer it and do the majority of the braking... I'd suggest that the front tyres are for more important, hence why the front tyres wear out considerably quicker than the rears!?!?!?!?

 

[Deleted member 7659]

I agree with LeonR ref having your newest/best tyres on the back. Not sure I'd say I couldn't care less about the fronts, though!

The front tyres do take more load - however if one fails you tend to get understeer which is easier to control. If a rear tyre fails you get oversteer - and good luck keeping it out of the barriers!

If you bed tyres in on the back they also last longer - then when you need new fronts swap your part worn tyres to the front and they'll last much longer than if they've only been fitted on the front.

Bigger the tyre the more important the remaining tread depth for wet weather driving - if your outer edges are shot you end up creating a perfect aquaplane if the tread is very worn as it'll only be able to disperse water from the rear of the tyre. Effect will get worse the faster you go.

Adrian

 

[chiefsilverback]

How do you control a car if one of the steering, driving and major braking tyres has failed? If anything, you'll brake, the car's weight will be transferred to the front, the failed side will dip even further, lifting the opposite rear tyre off the road and leave you trying to control a car that's effectivley on 2 wheels!!

A front tyre blow out on a FWD car will put you in just as much **** as a rear tyre...

The bottom line is all of your tyres need to be well maintained, but I'd still argue that on a FWD car the front tyres are more important...

 

[adam.mt]

Furthermore, if you are involved in an accident where breaking distance is an influence your insurance company will insist 2mm is the minimum tread depth, not 1.6; i.e. they have their own set of rules!

 

[LeonR]

The one about the back tyres would be clear if you ever went to the Ring.......
If you ever raced your LCR on the limit you'd have noticed how easy it is to correct unwanted movement in front, back breaking out however means the end of your trip.
I mentioned 2.5 mm in front with good tyres (not the tyres you can buy secondhand through internet)

 

[chiefsilverback]

Pushing my one on the track I've found that straight out the showroom the LCR has a real liking for understeer during highspeed cornering and the back will only break out if you lift off or brake during that cornering.

Because of it's understeer biased setup front tyre grip is even more important as it will reduce your chances of the car running too wide causing you to make the sort of correction that could lead to the back end going AWOL...

 

[Deleted member 7659]

Grip, yes - blowout, no. I think we're arguing the toss over similar arguements

Effectively you want all your tyres to be matched, and with good tread. Fronts do most of the work, therefore need to be in good nick. If you want to avoid a tyre failure-related visit into the scenary then good rear tyres are more important.

The way to control a front tyre blowout is to bleed speed off gradually - clearly if you're cornering at the time it won't make any difference as you won't have time/space to do anything about it. If a rear tyre goes you're really a passenger and can't control it since you don't have any single factor (eg steering, braking, throttle) that you can use to bring it under control without more than likely making the loss of control worse - it might behave, or it might not depending on failure mode of the tyre.

I used to work as a primary safety (accident avoidance) engineer & test driver so my opinion is based on trying the different options out.....

In the Cupra R's favour is the fact the wheel's are 18" diameter so even if the tyre disintigrates you've still got the rim to drive on until that breaks so you're unlikely to get the opposite corner wheel lifting. It's an emotive subject and everyone's entitled to their preference.

 

[chiefsilverback]

From personal experience I can tell you that the LCR alloys aren't the strongest things in the world!!

 

[Snoopcousins]

New tyres put on front or back?

Old thread, new question!

My Leon FR TDI has done 10k miles and im replacing the front tyres with Goodyear Eagle F1's. I just need to know whether i should put them on the front or back?

I want to put them on the front to see what they are like as havnt used them before but want to do whats best!
General consenus on here seems to be put new tyres on the back. Does this just mean the 'better' tyres on the back?
Since the car has only done 10k miles the rear tyres should still be ok (look fine to me) so in this case can the new F1s be put on the front?

Only good thing i can see fromn swapping the new tyres to the back is that after another 10k miles or so the last 2 Potenza's put on the front would need changed and then id have 4 Eagle F1's on the car.
Would the handling be ok with Potenzas on the front and Eagle F1s on the rear (or other way around)??