A star tyres , myth or fact

[Mob17]

Bought a 2011 X5 40D today with comfort seats. They are very comfy! Love the car, even with 20” RFTs the ride is way more comfortable than my previous car, a C63 on 18”. Was a bit worried about the 20” but think i’ll keep them. Will post a thread soon.

Car has brand new * rated tyres, so will not be replacing for a while.

[X5Sport]

[quote="Mob17"]
Car has brand new * rated tyres, so will not be replacing for a while.
[/quote]

At least for 15,000 miles or so, and congrats on the purchase 

[Mob17]

[quote="X5Sport"]
[quote="Mob17"]
Car has brand new * rated tyres, so will not be replacing for a while.
[/quote]

At least for 15,000 miles or so, and congrats on the purchase 
[/quote]

Thanks Good news, more than the 10k im used to!

[Ducklakeview]

Ok, have read through this with interest, and a few other threads on the subject. My car (Staggered 40d on 20") currently has star marked Dunlop Sport Maxx all round, and I will only be replacing with star marked.. Luckily I have accounts with a couple of tyre wholesalers, and a balancer/fitter at my unit. So hopefully the sting won't be quite as bad...

Mike

[Macapaca]

Just in case anyone is still trying to work this out...I've a 3.0SD MSport with 19" staggered set up. 235/45 fronts and 255/40 rears. I replaced all four with new Continentals.

The transfer case clunking that ensued was extraordinary. After a process of elimination (and after being advised by two BMW Indies that it wouldn't be the tyres - as they were the correct size, all the same tread pattern and reputable manufacturer etc)... I decided to change the tyres to a set of BMW star marked Pirelli P Zeroes. Which solved the problem.

Now here's the interesting thing...when the Continentals were taken off and a front and rear stood next to each other, there was a large difference in diameter (20mm). When the Pirellis front and rear stood side by side their diameters were identical - even though they were stamped with the same width/aspect ratio as the Continentals. So Pirelli 'massage' these specific tyres so they have the same circumference and bingo, the star marked tyres do their job.

[Mob17]

Interesting. Are there any non run flat 20” * options out there?

[Chrispy]

[quote="Macapaca"]
Just in case anyone is still trying to work this out...I've a 3.0SD MSport with 19" staggered set up. 235/45 fronts and 255/40 rears. I replaced all four with new Continentals.

The transfer case clunking that ensued was extraordinary. After a process of elimination (and after being advised by two BMW Indies that it wouldn't be the tyres - as they were the correct size, all the same tread pattern and reputable manufacturer etc)... I decided to change the tyres to a set of BMW star marked Pirelli P Zeroes. Which solved the problem.

Now here's the interesting thing...when the Continentals were taken off and a front and rear stood next to each other, there was a large difference in diameter (20mm). When the Pirellis front and rear stood side by side their diameters were identical - even though they were stamped with the same width/aspect ratio as the Continentals. So Pirelli 'massage' these specific tyres so they have the same circumference and bingo, the star marked tyres do their job.
[/quote]

See now this is the sort of post a thread like this needs.  Very specific in nature, brief and to the point. 
And with the extra info around the 20mm (which is a lot) difference in diameter it has actually made me re-think my future tyre replacement......  :noexpression:

It also answers my questions about the staggered setup and the manufacturer doing "extra things" to the tyres to make the RR the same front to rear, and also compared to other reputable brands (not your Wan Li ditch finders).  Curious about the manufacturing process still although that's kind of irrelevant other than to service my own curiosity.  Also curious as to why BMW are not more up front about this, or educate their dealers better to advise customers that this is the case with X-Drive cars. 

Ask most people off the street (myself included prior to owning the X5) and they won't have a clue what wind-up is on a 4x4, let alone how a staggered setup massively increases the risk of this happening.

I am due a pair of fronts by the looks of things quite soon as the outer shoulders are fairly worn.  The rears are not too bad but have a bit of feathering on the inner shoulders instead.  As such it would be nice if I could replace them as pairs rather than all 4 at the same time, simply to spread out the cost a little......With * marked tyres I'm now believing this makes this possible?.....

[X5Sport]

Technically BMW are up front about it.  They tell you to only use BMW Approved parts - and that includes tyres.  They don’t have any obligation to tell you why.  I completely agree that a bland comment in an Owners Manual is nowhere close to good enough though.

The car manufacturers are trying very hard to get to a position where you can only go to them through their ‘approved’ network for maintenance.  I would not be in the least bit surprised if sometime in the not too distant future, use of anything other than factory approved parts puts owners in breach of type approval and makes the car illegal. 

The motor industry around the world is very powerful nowadays as it makes a lot of money, employs significant workforces and pay large amounts of tax.  Governments don’t have the balls to take them on, or the trade unions making up the membership of the company’s Board.

As an aside, whilst looking for a winter alloy set for my new 220xD Gran Tourer I found a number of different car makes now have specific diameter tyre sets with the own code letters.  That begs a question.....if these are specialist sets can they be used in place of ‘*’ marked with no detrimental effects?

Is a tyre set for a Merc (marked MO) made the same way and in the same mould as say a ‘*’ tyre, just with the sidewall letter changed?  I don’t know the answer, just asking.

[Chrispy]

I think its the same with warranty claims and servicing.  During your warranty period you don't invalidate it if you have your car serviced outside the dealer network and use OEM parts.....but in practice I'm betting most stick to the dealers as they don't know this, and also the risk that the dealers (regardless of the legalities around this) will make your life difficult in the event of a claim......

Now tyres are an interesting one in that pretty much anyone who hasn't heard of * marking etc would assume they can throw whatever rubber they want on the car and that's fine - I think considering the potential implications (and I don't think BMW are alone in this with other AWD systems being prone to wind up to varying degrees) it needs to be emphasized more that this is the case......but then would that prompt people asking why, meaning BMW have to open up about the whole thing, and so on?

Did we determine if people had warranty claims declined on the basis of using "the wrong" tyres?  I can't remember.

[X5Sport]

In the dimness of distant memory, I think the answer was yes they have, but I also seem to think that these were AUC cars and had been supplied with those tyres and it was challenged.  Nothing in the last couple of years though - hence it being dim  :-[

If I was good with ‘search’ I would try and find them.

[Spandex]

[quote="Macapaca"]
So Pirelli 'massage' these specific tyres so they have the same circumference and bingo, the star marked tyres do their job.
[/quote]
I think it’s worth being clear, no one is ‘massaging’ anything. The stated tyre sizes on the sidewall should mean they’re all identical. All Pirelli have done is make them exactly to spec. The issue is that without standing your tyres side by side you have no way of knowing (other than buying star marked) if they’re made exactly to spec or not.

[Graeme]

I'd have thought for an accurate assessment they should be fitted and inflated to the pressures indicated either front and rear to low load or both to heavy load, and the circumference around the centre measured making sure the tape does not go into a groove!  Graeme

[Mob17]

[quote="Mob17"]
Interesting. Are there any non run flat 20” * options out there?
[/quote]

Any recommendations?

[Digidick]

[quote="Mob17"]
[quote="Mob17"]
Interesting. Are there any non run flat 20” * options out there?
[/quote]

Any recommendations?
[/quote]

Think quite a few on here have used MICHELIN Latitude Sport 3 but prices are as much as runflats I believe so if it's a cost gain rather than a comfort gain you want then I'm not sure you'll get it.

[Spandex]

[quote="Graeme"]
I'd have thought for an accurate assessment they should be fitted and inflated to the pressures indicated either front and rear to low load or both to heavy load, and the circumference around the centre measured making sure the tape does not go into a groove!  Graeme
[/quote]
I understand where you’re coming from, but I’m not sure it’s necessary. Tyres are incredibly stiff, and don’t really stretch like balloons as they’re being inflated. It wouldn’t hurt to,do it your way, but I think a side by side test before fitting would be more than sufficient.