[pmsteinm]

Last week I had my summer wheels dropped off to get the PZeros swapped out with the 4S. I said I wanted the Star BMW marked tires just because those are the OEM spec (not necessarily better, but just because). There are 2 BMW part numbers for the rears. The only marked difference is the tread depth (9.5 vs 9). When I got the tires I saw there was no star on the rears, and a star on the fronts. Dealer said this is fine but I decided to email Michelin and amazingly they responded with this:

You can use the Pilot Sport 4 S 285/35ZR20/XL ASY 104(Y) MSPN 09209 in place of the Pilot Sport 4 S 285/35ZR20/XL BMW ASY * 104(Y) MSPN 70968. The slightly shallower original tread depth (OTD) of MSPN 70968 makes them about 3/4 lb. lighter but there are no other differences in terms of their specification.

So it seems the BMW spec is just to shave the tires down a bit. The only other difference is the rears are made in USA, and the fronts in France. This should make the car more benign at the limit because the fronts will surrender first.

As a side note one of the front tires has no weights on it. Either an amazing job balancing or they forgot. I'll find out in April when I put them on.

[logicators]

Originally Posted by pmsteinm

Last week I had my summer wheels dropped off to get the PZeros swapped out with the 4S. I said I wanted the Star BMW marked tires just because those are the OEM spec (not necessarily better, but just because). There are 2 BMW part numbers for the rears. The only marked difference is the tread depth (9.5 vs 9). When I got the tires I saw there was no star on the rears, and a star on the fronts. Dealer said this is fine but I decided to email Michelin and amazingly they responded with this:



So it seems the BMW spec is just to shave the tires down a bit. The only other difference is the rears are made in USA, and the fronts in France. This should make the car more benign at the limit because the fronts will surrender first.

As a side note one of the front tires has no weights on it. Either an amazing job balancing or they forgot. I'll find out in April when I put them on.

Lol.

Can you please share the correct front part number as well? I will be in the same boat in a few months. Would have used PZeroes for another season but one of the rears got a nail right before switching to all seasons for winter, and I rather not use a patched tire.

[pmsteinm]

The fronts are MSPN 22176 (BMW) or MSPN 33200 (Standard with more tread).

I emailed them back about those as well and if there are any differences in the compound and asked about the outer tread block being slightly different on the fronts vs rears.

Normally I order from Tire Rack (which has both) but this time around the dealer was the same price.

[pbonsalb]

This is interesting. Some sources say the rubber compound varies among the various car brand versions of the Michelins (Mercedes, BMW, Ferrari). But if Michelin says they don’t then they don’t, as long as it was someone knowledgeable at Michelin answering the question.

[pmsteinm]

I know OEMs can spec different compounds or whatever. It seems in this case all they spec'd was less tread depth. My first CTS-V did that with the TPC spec Goodyear Eagle F1 Supercar tires.

I figure if the compounds were different I would get the "you can't mix" warning from Michelin. I can see BMW asking for a shaved spec since that will help the press review cars handle a tiny bit better. For actual owners who cares because you can wear that extra tread off during tire break-in.

[OCDoningtonF90]

Originally Posted by pbonsalb

This is interesting. Some sources say the rubber compound varies among the various car brand versions of the Michelins (Mercedes, BMW, Ferrari). But if Michelin says they don’t then they don’t, as long as it was someone knowledgeable at Michelin answering the question.

Here’s one example breaking down the differences between the 2 tires:
https://youtu.be/COA630Juf_U?si=enbIV2xL39rRdDyq

[pbonsalb]

That is completely different from what pmsteinm posted. I think the Michelin development engineer knows better than the Michelin press guy answering an email. There is way more to the difference than 1/2mm of tread. I wanted to go 285/295 or 295/305 for my next set, but that will mean losing 1 or both BMW versions of the 4S and substituting a Mercedes or Ferrari version of the 4S.

[logicators]

Originally Posted by pbonsalb

That is completely different from what pmsteinm posted. I think the Michelin development engineer knows better than the Michelin press guy answering an email. There is way more to the difference than 1/2mm of tread. I wanted to go 285/295 or 295/305 for my next set, but that will mean losing 1 or both BMW versions of the 4S and substituting a Mercedes or Ferrari version of the 4S.

What’s the benefit of going these higher sizes?

[pbonsalb]

I have wider wheels and the stock size tires look pinched on them. I generally go wider wheels and tires on my cars. The factory sizes are a compromise for fuel economy, cost, ride, and handling.