[Cero ceto]

Is it only RFTs which have a BMW star on them showing that they are approved by BMW? Or can I purchase BMW approved tyres (with star) which are non RFTs to replace my current ones?

[dopper99]

All M cars and M140i/M240i have non run flats which are typically Michelin’s or Continental’s and they would be star rated.

[pdk42]

What does the star rating really deliver? I've put MPS4 tyres on mine (not star rated AFAIK) and they are worlds better than the Bridgestone RTFs that came with the car.

[Sasquartch]

I always thought star rated tyres were to ensure compatibility with X drive and it was less important with S drive

[Cero ceto]

Yes that's my understanding, however I was hoping to purchase non RFT tyres which are star rated by BMW for my X Drive! But I expect they don't exist!

[Soul_Glo]

Apparently the MO (Mercedes Approved) and the BMW * are to do with rolling diameter: quite a few BMW are with staggered wheels, so in order to keep the rolling diameter identical but with different tyre sizes front/rear the MO and * are meant to tweak the sizes ever so slightly to ensure minimal differences.

Even more important on the xDrive BMWs where the centre differential takes the brunt of any differences between front and rear (my X3 has 235/50/18 front and 255/45/18 rears)

For a normal RWD BMW I would be more concerned about getting some premium tyres than the * ones.

Rassi off PH

Personally, I have noticed no difference without the star marked tyres.

[dopper99]

Originally Posted by Surg_Capt_R

Rassi off PH

Personally, I have noticed no difference without the star marked tyres.

Indeed. I fitted MPS4s tyres to the rears of my old M3. I noticed no difference - well ..... other than shed loads of grip.

[IK6SPEED]

Originally Posted by SSIIJAR

Is it only RFTs which have a BMW star on them showing that they are approved by BMW? Or can I purchase BMW approved tyres (with star) which are non RFTs to replace my current ones?

Star rated tyres have modifications to the generic version required by BMW (or another Manufacturer) they required after testing if they wanted those tire models to be sold OEM on newly produced cars.

Obviously the lure of hundreds of thousands/millions of tyres on new vehicle is too much to pass on.

Sometimes it’s actual size or design of tread as in the MPSS 295/35/19 and other times is has to do with the actual compound. Note the EU Tyre label show a wet weather difference in braking between the MPSS and MPSS Star version iirc. Note that MPSS are not RFT to answer your other question.

It has nothing to do with X drive. You could easily put different size Star Version tires and screwup X Drive.

As for MPS4S, if BMW finds the generic acceptable, there would not be a Star Version.

Likewise, there is no law that you must use Star Versions on your vehicle. BMW Engineers after testing find those to be better on BMWs than the Generic.

Upon Lease Return (or whatever term is for lease in U.K.) if you installed a tire that is not supplied on new BMWs (including generic version of a tyre instead of the Star version) it might very well not be accepted as a proper tyre for return.

[dopper99]

According to this MPS4S are fitted to M5 F90’s.

https://www.pistonheads.com/news/ph-...-details/36645

Tyres are 275/35 R20s at the front, 285/30 R20s at the rear and using Michelin Pilot Sport 4Ss.

and I don’t believe there is a star rated MPS4S.

In fact I’ve noticed these now seem to be the tyre of choice for 4wd high performance cars. I’ve seen them fitted to the Merc E63 also.

Whereas they are still fitting MPSS’s to RWD performance variants (ie my M3 and C63S both have them).

[IK6SPEED]

Originally Posted by dopper99

According to this MPS4S are fitted to M5 F90’s.

https://www.pistonheads.com/news/ph-...-details/36645

Tyres are 275/35 R20s at the front, 285/30 R20s at the rear and using Michelin Pilot Sport 4Ss.

and I don’t believe there is a star rated MPS4S.

In fact I’ve noticed these now seem to be the tyre of choice for 4wd high performance cars. I’ve seen them fitted to the Merc E63 also.

Whereas they are still fitting MPSS’s to RWD performance variants (ie my M3 and C63S both have them).

The MPS4S on the F90 are NOT the generic but actually a Star Version. You will note the tread is not as deep and a slightly different compound.

[Mikesmith2939]

I checked the Bridgestone website for tyres for my F30 xdrive and they recommend the DriveGuard RFT.

However they are not star rated.

[Wills2]

As has been said Star rated tyres are different from the generic versions compound/width and shape.

I have PS4S generic on my M3 and although the rear has more grip in a straight line the handling balance and crisp turn in has gone I have to have far more lock on the wheel going into corners, and the DSC intervenes far more often when I've got lock on the wheel.

These tyres will see the car out as it's going at the end of the rear if I was keeping it I'd be going back to star rated tyres.

[lethbridge]

Originally Posted by Wills2

As has been said Star rated tyres are different from the generic versions compound/width and shape.

I have PS4S generic on my M3 and although the rear has more grip in a straight line the handling balance and crisp turn in has gone I have to have far more lock on the wheel going into corners, and the DSC intervenes far more often when I've got lock on the wheel.

These tyres will see the car out as it's going at the end of the rear if I was keeping it I'd be going back to star rated tyres.

In you view on the F8X would you recommend keeping stock all round or stock front, PS4S rear? I certainly get that the PS4S just don't seem to work on the front...