[golty]

I'm looking to ditch the run flat P Zero's on my M340i to get some Michelin PS4S. I was thinking with the Black Friday offers now would be a good time.

Been taking a look round all the usual tyres shops and it seems that its quite hard to find a place that has both the front and rear tyres in stock with BMW OE * marked at good prices.

It would be easier to just be easier to buy the standard PS4s as well as been cheaper as you can get better deals on them. But I don't want to risk any warranty issues if they aren't star marked.

Anyone know if using a non-star marked tyre will definitely impact the warranty?

[Charlie (Wessex)]

Given that BMW offer tyres that aren't star marked, I suspect that they won't affect warranty.

https://www.bmw.co.uk/en/topics/owne...and-tyres.html

[HighlandPete]

Originally Posted by Charlie (Wessex)

Given that BMW offer tyres that aren't star marked, I suspect that they won't affect warranty.

https://www.bmw.co.uk/en/topics/owne...and-tyres.html

Where are you seeing non approved tyres listed? I seem to be missing something in print.

[Andy3661]

Originally Posted by HighlandPete

Where are you seeing non approved tyres listed? I seem to be missing something in print.

Mine came from BMW with none star marked tyres.

[HighlandPete]

Originally Posted by Andy3661

Mine came from BMW with none star marked tyres.

You mean fitted from the factory?

[Charlie (Wessex)]

Originally Posted by HighlandPete

Where are you seeing non approved tyres listed? I seem to be missing something in print.

I go in, put my details in - G21 M340i - and see what tyres they have. For example they offer 19" Mich PS4S that aren't star marked for summers.

Or with 18" Winters, they offer Nokian HKPL R3, Nokian HKPL 9 and Conti IceContact 3 TA that aren't BMW star marked.

[JNW1]

Originally Posted by golty

Anyone know if using a non-star marked tyre will definitely impact the warranty?

In the handbook for my car the use of star marked tyres is only a recommendation - there's no mention of them being mandatory with a potential warranty implication if you don't use them.

I think a warranty issue with an X-Drive car is far more likely to arise if non-standard sizes are fitted; that could result in a difference in rolling circumference front to rear which can in turn cause problems with the transfer box (or at least so it's rumoured). However, if you fit tyres of the correct size, speed and load rating I can't see there being a warranty problem even if those tyres aren't star marked...

[Charlie (Wessex)]

JNW1 but....if they are offering non star marked on their accessory configurator, then if you took it to court, I don't think they'd have a leg to stand on.

[HeebieJeebies]

Tyres are a consumable, BMW would have to CATEGORICALLY state that consumables MUST be BMW approved to meet any resulting warranty claim.

The onus would be on BMW to prove that the non* tyres caused the problem in the uber slim chance that ANYTHING on the drivetrain went wrong and is alleged to be the cause and due to non * tyres that resulted in a warranty claim being denied.

You could take this to extremes, ‘your tyres sir, non approved, caused a ‘vibration’ that broke you’re electric windows’. Not ever gonna happen.

[Andy3661]

Originally Posted by HighlandPete

You mean fitted from the factory?

Yes from factory, they where Bridgestones.

[Keith_C]

To answer the original question, in a word, no, they don't have to be star marked, otherwise there would be plenty of cars stood still as PS4S were on back order for months and probably are still difficult to locate.

The star marked tyres have a slightly different compound to the non star tyres, there's a video showing the nuances of the two types, nothing us Joe Public are going to notice in normal day to day driving.

I have never bought star marked tyres in 15 yrs of BMW ownership and never had a problem regarding warranty and I've had some whopping claims.

Only ever had run flats on my 1 series, first chance I had I replaced them with standard, but good quality tyres and touch wood, I have never been stranded due to a puncture, so don't worry about that side of it and you always have the roadside assistant if you do, presuming the car is running a warranty.

[DRuw]

it does say that non-approved tires are a reason for warranty claim rejection here in the terms and conditions of the warranty in the Netherlands.
I roughly translate this in "any other than BMW installs except stars".

which is absolute BS in my opinion btw.....

[JNW1]

Originally Posted by Charlie (Wessex)

JNW1 but....if they are offering non star marked on their accessory configurator, then if you took it to court, I don't think they'd have a leg to stand on.

I think we're saying the same thing; star marked tyres are only a recommendation so if BMW tried to reject a warranty claim on the basis they're a requirement I agree they'd be on very thin ice.

But personally I think any talk about warranty claims being rejected purely because star marked tyres weren't fitted are just internet rumour. It's similar to all those people who know someone who's been prosecuted for speeding when they were only the odd mph over the speed limit; never seen any evidence to prove it and never seen any evidence to prove BMW have rejected a warranty claim for not having star marked tyres fitted either!

[DRuw]

here is a copy of the general terms and conditions from the bmw.nl site (yes in dutch). I'm pretty sure they align with other countries.
The motor management thing which is always part of discussions is below it btw
Still not saying it's BS but it is written down...

edit: can't get my phone screenshot readable for some reason...???

[Talisman77]

Howdy - I got my car with PS4S* all round. A couple months back the rear tyre got a puncture from a nail, so I took it to dealer and inquired about getting a set of rears to replace. Turns out they ordered PS4S (non star) but I pushed back as I was keen to keep them all * (the * represents the first batch of tyres out of the mould from manufacture since these tend to be the highest quality, and are subject to tighter tolerances to make the grade).

This is important, because if your tyres are outside of tolerance they'll still be safe etc, but can cause premature wear on the transfer box and/or juddering on accel/decel as the car tries to compensate accordingly. It's the same deal with ensuring the tyre tread isn't too far out between the tyres either. When I pressed the dealer on the specifics regarding mixing * and non-*, they said there's nothing inherently wrong with it BUT if there was an issue with something like juddering or transfer box doing something weird, BMW will just turn around and say "ensure the tyres are * marked all the way around" and before you know it you've sunk £xxx into tyres that may or may not be viable on your setup.

Ultimately I insisted on * marked - I don't mind paying the extra given tyres are the only contact between myself and terra firma, and it's less hassle in preventing any future excuses/BS from issues arising. When the dealer checked, they had none in stock, contacted their tyre supplier, also none in stock. The supplier phoned Michelin who couldn't check due to a technical issue on their end (lmfao). BMW UK also had no stock nationally.

The last port of call was BMW AG (Germany) and lo and behold they had some there. Of course, since the tyres had to be imported from Germany, the price nearly doubled since I couldn't get price matched from Blackcircles

[danorman777]

Originally Posted by Talisman77

Howdy - (the * represents the first batch of tyres out of the mould from manufacture since these tend to be the highest quality, and are subject to tighter tolerances to make the grade).

I am not sure this is correct. According to many sources, star marked tyres and modified from non star marked tyres. They have slightly different compounds and construction. There is a YouTube video confirming this from an independent tester.

[Charlie (Wessex)]

I take the view that if a car is so sensitive to tyres that it has to only have * marked tyres, then it isn't a particularly well manufactured car. I think we all know that there are huge tolerances built in to things. Sure a * tyre might match the car 100%, but TBH I am more than happy with a 95%+ matching. In well over 30 years of driving, and taking a lot of interest in the condition of my tyres, I'm more than happy to have non * marked tyres on my car.

[HighlandPete]

Originally Posted by Charlie (Wessex)

I take the view that if a car is so sensitive to tyres that it has to only have * marked tyres, then it isn't a particularly well manufactured car. I think we all know that there are huge tolerances built in to things. Sure a * tyre might match the car 100%, but TBH I am more than happy with a 95%+ matching. In well over 30 years of driving, and taking a lot of interest in the condition of my tyres, I'm more than happy to have non * marked tyres on my car.

Historically the xDrive transfer box has been a very sensitive bit of kit. E83 X3 was very, very sensitive to tyres. One of the reasons those with experience inside and outside of BMW (like tyre suppliers) became very aware of tyre compatibility. Seems it has got better over time, but... if there are suspected drivetrain issues, BMW will have the tyres checked as the first point of reference. Some users have had to get a set of star marked tyres fitted, before the warranty process kicks in.

As to the design of xDrive, if the RC front to rear is too wide a tolerance, the transfer box has to 'absorb' the difference by clutch slip (added heat and wear) and/or tyre micro scrubbing. There is no other way AWD systems get rid of badly matched tyres. I imagine you have heard of 'tyre shaving', the mechanism to keep many an old AWD design from crunching up transmissions and drivetrains.

I see it this way, tyres are part of the xDrive system, both for longevity and as important, torque transfer sensitivity.

[Charlie (Wessex)]

That might be the case Pete, but if there are no suitable tyres on the market then that is a failure by BMW. If there were star marked all season RFTs then I'd get them - or even star marked all seasons. I am not driving through the winter months on summer tyres, and I am not going to get a set of full winters as they aren't needed on the south coast of England. Thought maybe I should get some Conti TS860s (or 870s) to stick with the star mark.

[HighlandPete]

Originally Posted by Charlie (Wessex)

That might be the case Pete, but if there are no suitable tyres on the market then that is a failure by BMW. If there were star marked all season RFTs then I'd get them. I am not driving through the winter months on summer tyres, and I am not going to get a set of full winters as they aren't needed on the south coast of England. Thought maybe I should get some Conti TS860s (or 870s) to stick with the star mark.

I understand the dilemma. I've seen your thread on the CrossClimate tyre situation as well. I'd personally not fit the two different spec' versions on my car, even RWD. Too much experience of what appears the same, being a mis-match with odd driving characteristics, (or worse).

It's a shame BMW UK don't support All Season tyres. (Not many years back that was the same with winter tyres). Staggered is where any issues may exist with xDrive. If you are on a square setup, then the RC 'front to rear' isn't a problem.

[Charlie (Wessex)]

I think I'm probably erring to CC+ front and rear rather than mixing.

[Scottish0177]

Found this article from a few years back ref tyres and different car marques.

some of what they say makes sense, however still not sure about the need for specific star marked tyres....But what do i know?

Be handy if BMW put out more info out there so folks could understand the reasoning and benefits.

Familiar with homologated tyres? Know what all those sidewall markings mean?
21MAY
By Tom Boote

To most drivers, trying to understand the markings on a tyre sidewall can be confusing. It’s hardly surprising, since a casual glance at a tyre suggests there’s a lot to take in. Apart from the tyre manufacturer brand name – for instance, Continental – and the product name (for example, “ContiEcoContact 5”), all the other information looks like a jumble of characters at best, or, at worst, a mysterious, indecipherable code.

It’s enough to make most UK drivers look away and not bother trying to understand the meaning. But that would be a mistake, since the information on your tyre sidewall is important.

Many motorists understand how to recognise the tyre size – for example “215 55 R 17” – but as for the rest… we tend to simply ignore it. And that’s a mistake, especially if you drive a high end car, like an Audi, BMW, Jaguar, Mercedes-Benz, Mini, Land Rover, Tesla, Maserati or Porsche. Why? Because the information on the tyre sidewall is there to help you get the best driving experience from your vehicle.

If you want to get the maximum performance from your vehicle, and fully benefit from the unrivalled characteristics of an approved, dedicated premium tyre – such as a Continental SportContact 6 – you should definitely take an interest in the sidewall markings.

‘Homologated’ tyres are approved by your vehicle manufacturer
But first, a quick bit of industry jargon. The technical term for a tyre that’s been specifically developed with – and approved by – a vehicle manufacturer, is “homologated”.

The vehicle maker can be identified on the tyre sidewall, since each one has their own specific code. Some of these codes are easier to understand than others. For instance, Mercedes is MO, and Audi is AO, but others aren’t so easy to guess. N1? Nissan, right? No. Believe it or not, N1 is actually Porsche.


Example of a homologated tyre for Audi – manufacturer code “AO”

Here’s a list of homologation codes for some of the world’s leading automotive marques.

Manufacturer OE Key
Audi A0, A01
Audi quattro RO1, RO2, R03
BMW *
BMW / Mercedes *MO
BMW / Mercedes Runflat *MOE
Jaguar J
Land Rover LR
Maserati MGT
Mercedes-Benz MO, MO1
Mercedes-Benz Runflat MOE
Porsche NO, N1, N2
Tesla TO

Quick guide to tyre sidewall markings
HOMOLOGATED TYRES – SIDEWALL DESCRIPTION

Homologation. It’s all about fitting the right tyres for your car
Homologation works like this: a tyre manufacturer – like Continental – designs, extensively tests, and produces a new generic tyre model for sale. Continental’s award winning ContiPremiumContact 5 is a superb example – a very high quality premium tyre that can be used on a wide variety of car makes and models.

It’s at this point that the world’s leading car manufacturers begin to test this generic tyre, so as to determine how it will perform when fitted to their vehicles. This process takes in a wide range of criteria, such as weight, grip, performance, and handling. What the car manufacturers are looking for is whether the generic tyre brings out the best characteristics and attributes – handling for example – that the vehicle itself has been engineered for.

After an exhaustive testing process, the feedback from the car maker is taken on board by the tyre manufacturer, any necessary modifications are made, and – at the completion of the process – the homologated version of the tyre is approved by the vehicle manufacturer. It’s then produced by the tyre maker, bearing the car manufacturer’s homologation code on the tyre sidewall.

This thorough and painstaking process can take up to two years to complete, which is why the selection of homologated tyres is limited mainly to premium tyre manufacturers, like Continental Tyres. And the result of all this hard work? A superb set of bespoke premium tyres, created to work in perfect harmony with your specific vehicle.

What will you notice with homologated tyres?
Consider this. You’ve bought a four year old Audi. You purchased it because you love the car, its stiff suspension, tight handling, and great acceleration. And then – after a year – you need to change the (generic) tyres. Your local tyre fitter recommends homologated ContiSportContact 5P – approved by Audi for your car. You purchase a brand new set of these tyres.

So, what can you expect to notice? More than anything else, it’s that the things you love about your car already are now so much more noticeable, such as how the ride feels even better, and the handling feels that much tighter. And when you put your foot down, you really get to experience that feeling of oomph from your car! And don’t forget, there’s also the superior feeling of grip that homologated tyres give you, providing sharper, quicker braking – especially in wet weather conditions, significantly reducing your stopping distances.



Homologated tyres – safer than generic premium tyres?
Yes. Generic, non-homologated premium tyres – such as Continental’s – are all engineered to a superb level, and provide drivers with optimum handling, grip and braking performance, no question. They’re ideal to provide the best performance across all vehicles, offering great safety characteristics.

However, when compared to bespoke, homologated versions that have been created specifically for you car – it’s no competition. There’s simply no comparison. Homologated tyres are a much better choice, since they’ve been built to specifically enhance the characteristcs unique to your vehicle, exactly as the vehicle manufacturer intended. As a result, safety characteristics are enhanced.

How can generic premium tyres vary from bespoke, homologated tyres? Sometimes the addition of different material technologies are needed for the tyre to fulfil the vehicle manufacturer’s needs. Or in some cases, the tyre tread pattern is modified. It’s often the case that the tyre’s rubber compound ingredients are subtlely changed, ensuring it performs exactly how it needs to, so as to bring out the best characteristics of your vehicle.

And once the homologated tyre is approved, the vehicle will be set up to its specification. This ensures that the suspension works in perfect harmony with the tyre to enhance the ride experience, handling characteristics, and acceleration. The simple trust is, if you truly want to get the most from your vehicle, and experience the original performance characteristics it is capable of, the best way to do so is by investing in the correct bespoke homolagated tyres.

If you’re unsure about homologated tyres, talk to Protyre
Get in touch with your local Protyre garage today, for impartial, expert advice on homologated tyres. Our experienced team of tyre professionals can help you find the right tyres for your car.