Mclaren 570s new tyre problems

[Dacey]

Hi. I've recently replaced the rear tyres on the Mclaren with what I thought was like for like (Pirelli p zeros). I've covered about 60 miles on the new ones and even on a hot day with warm tyres the traction control is kicking in all the way through second gear and sometimes into third. Do tyres need to be run in? I've seen mixed opinions? If they don't then these tyres are shocking and have absolutely ruined the performance of the car!

[V8 Stang]

Having had P Zero’s on a Mustang GT, im not surprised you have traction issues on a Mclaren.

They seem to amazingly have no grip, yet also eat themselves at an alarming rate.

The Michelin PS4’s are a world of difference.

[Dacey]

The ones on before were actually pretty good, which is why I went for the same again. If these don't improve they'll be coming off very soon! Thanks for your advice.

[130R]

They should feel better after a few hundred miles

[Mark-ri571]

From Continental website
There are a number of factors that will make your new tyres perform a little differently to your older ones.
Lubricants. During manufacturing, a release lubricant is used to help remove tyres from their moulds. This substance remains on the tread until it wears off on the road. Before it has completely worn off, it could reduce your traction.

Antioxidants. These are applied to help keep the tyre rubber from breaking down when exposed to environmental factors such as fluctuating temperatures and oxygen. They may make tyres feel slick at first.

Tread depth. New tyres will naturally feature maximum tread depth. This fresh tread is stiff, smooth, deep and could feel like unyielding, thick cushioning between you and the road at first. This may lead to something called squirm.

What is “squirm”?
Tread squirm, or tyre squirm, is a little bit of excess movement you might feel when steering a vehicle that has recently been fitted with new tyres. This movement comes from the flexibility in the rubber between the tread surface and the carcass.

[bordseye]

Dacey said:

Hi. I've recently replaced the rear tyres on the Mclaren with what I thought was like for like (Pirelli p zeros). I've covered about 60 miles on the new ones and even on a hot day with warm tyres the traction control is kicking in all the way through second gear and sometimes into third. Do tyres need to be run in? I've seen mixed opinions? If they don't then these tyres are shocking and have absolutely ruined the performance of the car!

Depends how loss of traction is measured. If it is done by a comparison of the rotation of the now old front tyres with the new rear ones then that could well be a reason. Somewhere in the electroniccy there has to be a calculation of how the rear is rotating compared to how it should be rotating and its a case of where that latter data comes from.

In my last Fezza I learned this when I couldnt get the car out of the rear brake rollers for an MoT test - the traction control saw the rears rotating freely when the fronts didnt move so it cut the throttle. Had to put the car into race to get out of the rollers.

[Earthdweller]

Dacey said:

Do tyres need to be run in?

Yes

[Dacey]

I've driven it pretty hard for those 60 miles too, purposely trying to ruff them up. Its roasting outside today, the roads are hot, tyres are hot, and the traction control is holding it back in third gear in a straight line.... it just doesn't feel right

Edited by Dacey on Saturday 17th July 16:27

[E63eeeeee...]

There was quite a big thing recently about how you can get both manufacturer-specific and generic tyres all branded as (e.g.) Pirelli PZero and you'd have noticeable performance differences between them. Any chance you originally had McLaren-specific tyres on originally, and replaced them with generic ones? Because I'm more surprised that they were ever good than that they suck now, my E63 came to me with new PZeroes on the front and the difference in front-end confidence swapping to PS4s-even with 5+mm still on the Pirellis- was amazing.

[Jimmy No Hands]

This is 100 percent true, although feel free to call me out on it. (But I promise!)

I used to work for a Northern Ferrari / Aston Martin dealer (notorious recently due to a naughty salesman) and I once came out to the valet bay to an absolute ruckus - albeit a very nice sounding one.

Someone was doing a burnout in a DBS, sending plumes of smoke everywhere. Upon further inspection I noticed a technician in the driving seat. Went over to my colleague and asked what on earth he was doing, thinking he'd gone a bit bananas. (This was a customer vehicle.)

He was removing the covering / lubricant on brand new rear tyres as the customer had requested (not sure they knew this was the method, mind.) because previously they'd had a near miss due to a traction issue with these particular tyres when they were fresh on.

So, it could be something similar?

[Dacey]

E63eeeeee... said:

There was quite a big thing recently about how you can get both manufacturer-specific and generic tyres all branded as (e.g.) Pirelli PZero and you'd have noticeable performance differences between them. Any chance you originally had McLaren-specific tyres on originally, and replaced them with generic ones? Because I'm more surprised that they were ever good than that they suck now, my E63 came to me with new PZeroes on the front and the difference in front-end confidence swapping to PS4s-even with 5+mm still on the Pirellis- was amazing.

It was the only Pirelli p zero I could find that was specifically for the Mclaren so I'm pretty sure it's the right ones, but it is an 'ncs' so maybe that's the difference from the previous... I dunno, I'm no expert as you can tell!

[Dacey]

Jimmy No Hands said:

This is 100 percent true, although feel free to call me out on it. (But I promise!)

I used to work for a Northern Ferrari / Aston Martin dealer (notorious recently due to a naughty salesman) and I once came out to the valet bay to an absolute ruckus - albeit a very nice sounding one.

Someone was doing a burnout in a DBS, sending plumes of smoke everywhere. Upon further inspection I noticed a technician in the driving seat. Went over to my colleague and asked what on earth he was doing, thinking he'd gone a bit bananas. (This was a customer vehicle.)

He was removing the covering / lubricant on brand new rear tyres as the customer had requested (not sure they knew this was the method, mind.) because previously they'd had a near miss due to a traction issue with these particular tyres when they were fresh on.

So, it could be something similar?

That's actually a damn good idea. Looks like I'll be in my local B&Q car park later giving the boy racers a show ; )

[voram]

Check your tyre pressures. Over-inflation either from a static cold start or due to increased temperature/pressure can be significant.

And if you're still struggling I'd be tempted to drop them 10% anyway and see what happens.

[addz86]

As above ^ check the pressures.

I recent changed from 8 year old Avon’s on my Caterham to R888’r and thought I’d ruined the car at first.

Turns out they were at 38psi rather than the usual 18.

[Kawasicki]

if the new tyres rear tyres have a different (smaller) rolling circumference than the old tyres then the traction control can think the rear wheels are spinning slightly and intervene.

[Dacey]

Cheers for the suggestions. I will update with an outcome when I get to the bottom of it.

[anonymous-user]

P-Zero is used as almost as a brand name for a range of Pirelli tyres, you can get P-Zero Rosso, Corsa, Nero or Assimetrico as well as just “P-Zero”.

The Pirelli website says that you should have the McLaren specific MC marked P-Zero PZ4 PNCS. If it’s not an MC marked tyre or is a different type of P-Zero that could well be your problem.

You need to find out exactly what’s been fitted.

Also if it was on the P-Zero Corsa before, which is possible as it’s their track-focused/ultra performance option for the 570, then there will be a lot less grip on the non-Corsa variant. What is fitted to the front of the car?

Edited by anonymous-user on Saturday 17th July 19:33

[Jasandjules]

It sounds like your driving style. The only thing I can suggest is I collect the car and use it for a month and then let you know........................

[samoht]

charltjr said:

Also if it was on the P-Zero Corsa before, which is possible as it’s their track-focused/ultra performance option for the 570, then there will be a lot less grip on the non-Corsa variant. What is fitted to the front of the car?

Was going to say this, if it's not the tyre pressures then most likely explanation would seem to be that you took off a stickier, trackday Corsa variant of the P Zero and put on a standard road version.

If you have the service history, you might be able to find the receipt when the previous set of rear tyres were fitted, which might specify which flavour of P Zero they were (assuming the actual tyres have been disposed of).

[peteA]

60 miles isn’t enough? 200/300 miles and a few heat cycles so see them ok, or at least as good as they’ll get depending on the tyre.

Not sure the burnout technique is a recommended method, not least on the drivetrain, hope it was warmed up