G31 Tyre preferences

[Sjl]

I’m looking at replacing all my tyres, wondered if anyone has recommendations as to brands?

Currently I have PZero4 XL, not run flats, as supplied by BMW, been thinking about Michelin pilot sport 4s, not run flat, as an alternative to the PZ4s which have been very good ….. anyone have any experience of these on a G31?

BTW I don’t need winter tyres … 

[Matthew]

2 hours ago, Sjl said:

I’m looking at replacing all my tyres, wondered if anyone has recommendations as to brands?

Currently I have PZero4 XL, not run flats, as supplied by BMW, been thinking about Michelin pilot sport 4s, not run flat, as an alternative to the PZ4s which have been very good ….. anyone have any experience of these on a G31?

BTW I don’t need winter tyres … 

I have the PZeros (runflat) on my G32 and won’t be changing brand when they need replacing. Especially if you have no complaints, stick with what you have. With my old F11, for a long time the only brand available in the size and load rating was Goodyear Excellence, when Michelins became available I thought I’d  change and regretted it. The car never felt great with Michelins - the grass isn’t always greener. 

Edited April 16, 2023 by Matthew

[Mr H]

Michelin Primacy 3 (runflat) on mine since new and they've been fine. Will probably need to replace the rear 2 later this year as they seem to wear at twice the rate of the fronts.......

[Procion]

Depends on your driving style, mileage and what you expect from a tyre. If you enjoy the cars performance and handling stay premium (PZ4 or P4S). If you just want “tyres” then anything mid-range e.g., Bridgestone, Yokohama, Goodyear etc. Whatever you decide on make sure they are BMW * marked if the car has Xdrive.

Pointless paying £250+ a wheel to drive like Miss Daisy.

[Ian W]

3 hours ago, Procion said:

 Whatever you decide on make sure they are BMW * marked if the car has Xdrive.

Could I ask why?  I'm thinking of going all weather next time and Hankook are well rated by Autocar, Whatcar etc but aren't BMW starred so why would it be problematic on an xdrive to fit them.  Genuine question, not being argumentative, just want to understand why.

[Procion]

The Xdrive system is very sensitive to variations in the rolling diameter of tyres, not only across axles left to right but also between axles. E.G. Front to Rear. 

There is a lot of information and debate about this on the web, well worth a look if you are interested. It's a very techy subject and not always simply explained.

BMWs own documentation states the following:
Notes and specifications for tyre / wheel exchange 
 General:
•    The tyre size, manufacturer and tyre tread must be the same on one axle.
•    To meet the BMW standards, the vehicle should be equipped with tyres from the same manufacturer and with the same tyre tread (tyres approved by BMW) on all 4 wheels.
•    The difference in tyre tread depth on one axle must not exceed 2 mm (control quality of suspension control systems and wheel alignment requirement)
•    The tyres with the higher tread depths must be mounted on the rear axle.
•    The DOT age difference must not exceed 4 years.
•    The tyre pressure must be adjusted when the tyres are exchanged.
•    Wheel exchange between the axles
The wheels may be exchanged between axles to achieve even abrasion. However, BMW does not recommend switching the front wheels to the rear or vice-versa. 
The wheel exchange may lead to the following customer complaints:
-    complaints regarding acoustics
-    Risk of increased lane groove sensitivity
Additionally for all-wheel drive vehicles:
•    The tyre size, manufacturer and tyre tread must be identical on all wheels; different tyre sizes between front and rear axles are only permissible if mixed tyres are fitted.
•    The tyre tread difference between tyres in all wheel positions must not exceed 2 mm (normal quality of the wheel control systems and wheel alignment requirement)

If you dig into how differentials work, then you will “get” where they are coming from with the above recommendations. The biggest problem is tyre manufacturers sizes are remarkably and majorly inconsistent between individual tyres.
* Marked tyres are strictly quality controlled to present accurate and consistent rolling diameters. * Marked tyres will all be within the prescribed tolerance when new.

Personally, from many years of Xdrive ownership I’m a little sceptical that these tolerances need to be so tight. My cars Xdrive power distribution is biased 90% rear 10% front, whereas on nearly all other Xdrive models it is 40/60. As a result, thanks to my big right foot, my car chews through rears at a rate of knots so I often end up with 6mm variations. 

However, avoid the guidance at your peril and be prepared for a growling noise from under the car and/or worst case, the need for a new transfer box!

I very much doubt the above will happen, at least you've seen what BMW say about it.

[Mr H]

On 22/04/2023 at 22:10, Procion said:

The tyres with the higher tread depths must be mounted on the rear axle.

Interesting they state this when the rears wear quicker than the fronts (on mine currently 6mm vs 4mm R/F) and they cannot be swapped front to rear (staggered). My intention is to swap the rears when they reach 3mm as by then the fronts should still be 5-6mm............

[Matthew]

On 26/04/2023 at 11:59, Mr H said:

Interesting they state this when the rears wear quicker than the fronts (on mine currently 6mm vs 4mm R/F) and they cannot be swapped front to rear (staggered). My intention is to swap the rears when they reach 3mm as by then the fronts should still be 5-6mm............

For a square set up this works and the main reason is traction, whether a front wheel drive car, rear or xDrive, losing the front end on normal roads at normal speeds is easier to correct than losing the rear end for the general populous. So they will always tell you to put the tyres with the most tread at the rear, unless a staggered set up of course.

[Mr H]

2 hours ago, Matthew said:

For a square set up this works and the main reason is traction, whether a front wheel drive car, rear or xDrive, losing the front end on normal roads at normal speeds is easier to correct than losing the rear end for the general populous. So they will always tell you to put the tyres with the most tread at the rear, unless a staggered set up of course.

Makes sense. I think my warped logic / interpretation was that putting tyres with most tread on the rear was at odds with what actaully happens with staggered (tbh I hadn't considered square set ups but even then with those cars that we do have (have had) we have always been advised by tyre place to put new tyres on the front (FWD)???

[Matthew]

On 28/04/2023 at 10:19, Mr H said:

Makes sense. I think my warped logic / interpretation was that putting tyres with most tread on the rear was at odds with what actaully happens with staggered (tbh I hadn't considered square set ups but even then with those cars that we do have (have had) we have always been advised by tyre place to put new tyres on the front (FWD)???

Average tyre places don't necessarily have the brightest people working there. Places like Costco will not fit new tyres to the front if buying just 2 when I put tyres on my FWD Vectra a long time ago (staggered excepted of course) and when I spoke to the fitter he was explaining the high level of training they go through. That is just one shop so I did some research and tyre manufacturers specify new tyres or tyres with the most tread to the rear.