A question on tyre tread depths

[White16valver]

Following on from the window tints thread, I was wondering about tyre tread depths.

I know the legal minimum is 1.6mm but I'm a bit confused - as I understand it there are two difference standards:

The MOT standard = 1.6mm across 3/4 of the tyre width.
The Police standard = must be 1.6mm across the whole width of the tyre.

Is this correct?

Does seem daft that you can pass an MOT, drive off, then get 3 points per tyre from the police...

 

[172 Dave]

Police standard is 1.6mm over centre 3/4 of the tread and for 90% of the circumference.

 

[Turkish]

I was always under the impression it should be 1.6mm across the centre 3/4s and visible tread on the rest. either way i would really avoid being less than about 2.5 anyway as thats not much especially in the wet.

 

[White16valver]

So they are the same standards then??

And does that mean that you could be running massive amounts of negative camber, to the point that your inside edges on the fronts were smoooooth but the rest was still legal?

 

[172 Dave]

yes but like an MOT you'd get advice, and it sounds like ur gamblin if runnin that amount of camber

 

[Revels]

Paul, just buy some new tyres on stop being so tight!

 

[White16valver]

shoosh!

lol

 

[Dave]

As long as the centre three quarters of the tyre show 1.6mm of tread the tyre is legal. So yeah in theory you could run massive amounts of negative camber and a whole eighth of the tyre on the inside COULD be bald. But remember it will only be an eighth as it is the CENTRAL 3/4. That leaves 1/4 of the tyre split either side of this central part, i.e. 1/8th of the width of the tyre.

Phew.

 

[Baby D]

i got told for my practical test and passed on that question

1.6mm around the whole circumference and the inner 3/4s of the tyre.. basically everything dave said!

 

[Karen]

What depth are the markers on the tyres?? Mine are getting a bit low :S

 

[cat171]

I'm pretty sure the markers are at 2mm.

 

[White16valver]

I thought they were 1.6?

Thanks for the info all

Now I can continue to drive like a loon and not worry about getting done for my tyres if I get pulled.

Er, I mean... LoL

 

[McBunny]

but sometimes using the makers isnt the right thing to doo look at this tyre its not down at the wear markers but its an illegal tyre due to that bar that runs all the way across is flat

 

[Dave]

Yup, that'd earn you 3 points.

 

[McBunny]

altho technically going by the wear indicators they are fine

 

[Weeman]

Canvas aint showing, then keep on going!

 

[JJsRT]

Haha.. does seem a bit weird as if you had say 205 width tyres and they were on the limiter you would still get more grip than a brand new 165 tyre (correct me if i am wrong!!)

Despite this still wouldnt let mine get under 2.5!

 

[White16valver]

Hypothetically speaking... on that tyre in the photo, if you were to remove the bar, you could carry on using it for a little while longer, no?

 

[JJsRT]

Haha you nutter

 

[White16valver]

Well racing teams use hand cut slicks so why not on the road? lol

 

[gaz16v]

you can buy road legal slicks with 2 grooves of 1.6ml tread on them cant get done for them and will pass a mot

 

[Karen]

Would it be really dodgy (for me) if I did a track day with my tyres almost on minimum?? :S I presume i'd be better off changing them in advance seeing as Im fairly crap on track?

 

[gaz16v]

not really u would screw a good tyre use the old ones

 

[Pat_986]

Would it be really dodgy (for me) if I did a track day with my tyres almost on minimum?? :S I presume i'd be better off changing them in advance seeing as Im fairly crap on track?

If its dry you would be fine, if its wet its another story!

 

[White16valver]

I'm guessing this one should be a trackday only tyre then? lol

 

[Brian]

interesting subject, I was reading in Auto Express the Government cars are changed at 2mm and police vehicles are changed at 3mm, apparently to avoid them getting too low between services

 

[Ambo]

I think the police would measure the tread depth rather than relying on the wear indicators! I assume they are at 1.6mm but wouldn't rely on it myself.

Karen...did Oulton park ok on front tyres that were fairly new...about 1000 miles! As said, if it's wet it could get interesting!! Depends how fussed you are about getting home on legal tyres too...

Might be worth measuring them as I always think they look lower than they are...

 

[Karen]

I think the police would measure the tread depth rather than relying on the wear indicators! I assume they are at 1.6mm but wouldn't rely on it myself.

Karen...did Oulton park ok on front tyres that were fairly new...about 1000 miles! As said, if it's wet it could get interesting!! Depends how fussed you are about getting home on legal tyres too...

Might be worth measuring them as I always think they look lower than they are...

Yeah I'm not worried about using new tyres if I do a track day, the thing Im more bothered about is the handling of the car when they are very low... or what I think is low :S there isnt really any difference in the marker to the tyre now, just a slight bit so I'll change them now regardless I think... they have done 22k and 4 track days!

 

[Ambo]

^^done well to get that out of tyres...assuming fronts of course!

 

[Karen]

^^done well to get that out of tyres...assuming fronts of course!

Yeah fronts! I guess I mainly drive around London and on motorways hence why they've lasted?

Maybe I should take a pic of the markers :S

 

[Ambo]

Yeah fronts! I guess I mainly drive around London and on motorways hence why they've lasted?

Maybe I should take a pic of the markers :S

...or buy a tyre depth gauge, cheap enough and then you know for sure what they are!

 

[Karen]

 

[Ambo]

^^think when they are actually flat/smooth from the tread across to the indicator then thats 1.6mm.

 

[White16valver]

Like this you mean?

LOL :clown: