[therealm3]

So I will be the first to admit with every modern BMW I have owned in the last 15 years I could not wait to junk the oe tires. Mostly cause they were run flats and I wanted PS2's, PSS's and now PS4S's. Yes, I am a huge fan of Michelin tires. Anyhow, I have always wondered if star spec tires would be any different and what that would mean. Well low and behold I stumbled on to this video on you tube and I must say, I hope those star spec 4S tires come in a few more sizes and something that may fit on a current or future car of mine , not just a g80/2. And it makes me want to spend some time digging through tire rack to see what other star spec (non run flat) gems maybe hiding in the litany of choices.

Thoughts?

[Tommi_Mav]

I saw that video too and was amazed by the amount of effort spent and R&D on just a tyre for a specific model. But of course it was for a flagship M car.

It doesn't mean of course that every star marked Michelin has the same compound as these PS4S*. The most important factor, IMHO, is for which car each star marked tyre is designed for and used as OE. This would give you an idea of what the final goal in road feeling and behaviour of the tyre was.

[J555]

Watched this video as soon as released, Jonathan is possibly the best tire guy for many years.

Unfortunately, this can't be applied to (*) tires in general, both because these are special (M3, non RFT), and most of others are RFT's of obsolete design. Yes, this opens the opportunity to fit the M3 fronts to the rear, but there are not many F3x cars running this size. Still, you would end up with different tires front/rear, as these tires come only in M3/M4 sizes.

As I kind of tire geek, I am aware of the specific tires; but never seen it in such detailed analysis. This year, I also fitted the K1 Ferrari spec PS4S fronts - just to see the difference. While I guess it is a very similar story (the tires are quite different from standard PS4S), I can't confirm yet, whether it is a good idea or not. Aside from the fun of such experiments, my intention was to further reduce the dry understeer. While that definitely works, I am not yet sure of the price paid in the wet.

Asked Jonathan, if he can extend the test group also with Ferrari and AMG specific PS4S one day, and I guess you know the answer It might be interesting to fit the entire set of AMG-specific tires for a similar platform (if they are available), but doubt somebody can compare them in the way Jon does.

btw, we had a local video comparing the star, and non-star Pirelli's (if I remember well). They are different, indeed. Still, I consider buying something as F1 Asymmetric 2 RFT (*) over standard Asymmetric 5 as absolutely stupid idea; no matter the (higher) price

[therealm3]

Yeah, for now it seems the star 4s is reserved to new g8x sizing, but with that much r and d into it, hopefully it will trickle down in other sizes. For someone looking for all out dry performance, it's cool to see it would be worth paying extra for.

[Desertnate]

I guess I need to go back and take a look at the video. Really interested now.

Originally Posted by therealm3

Yeah, for now it seems the star 4s is reserved to new g8x sizing, but with that much r and d into it, hopefully it will trickle down in other sizes. For someone looking for all out dry performance, it's cool to see it would be worth paying extra for.

Tire Rack has "start spec" PS4S's for my OEM 19" F32 RWD staggered sizes.

[therealm3]

Originally Posted by Desertnate

I guess I need to go back and take a look at the video. Really interested now.

Tire Rack has "start spec" PS4S's for my OEM 19" F32 RWD staggered sizes.

Indeed they do! If they are the same spec as the ones from the video, might be worth a shot next time around.

[ZM2]

Originally Posted by therealm3

Indeed they do! If they are the same spec as the ones from the video, might be worth a shot next time around.

They’re not: https://f87.bimmerpost.com/forums/sh....php?t=1828377

[J555]

Originally Posted by therealm3

Yeah, for now it seems the star 4s is reserved to new g8x sizing, but with that much r and d into it, hopefully it will trickle down in other sizes.

Absolutely no chance. The PS4S is awarded for the excellent compromise between dry and wet performance, along with low weight, low rolling resistance, tread wear, and good level of comfort. This version is vehicle-specific, and moves the compromise towards the dry performance, which is unwanted for general use.

If you are interested more in dry performance, you can consider some other tires, or take a look at AMG, Ferrari or Porsche versions...

[F32Fleet]

All I can say is that the star spec tires (S001) on my 4-series were almost dangerous in the wet.

A lot of automakers do this or something similar. For example the tires on our C300 come only from Continental and they're the worst tires I've ever owned in terms of wear. The tires are simply unnecessary for a mundane 4-cylinder.

[MacklinUSOB]

As hinted in the video, expect to see some of the compound changes incorporated into the upcoming PS5 line of tires. These G8X star PS4S are far more special than any of the star RFTs for F3/2X, them along with the star PSS on F8X have been a generation behind for more than half of their production runs.

These stars look to be great tires, they've clearly used them as a test bed for their next aftermarket offerings with so much time invested.

[ssandman]

Thanks for sharing the video, very informative!

I recently purchased my F32 18 440i coupe w/ track handling package. The front tires are 225/40R19 and rear 255/35R19.

I think I've decided to replace the current Potenza S001 runflats with Michelin Pilot Sport 4 S.

I stumbled upon both standard and 'BMW Star' options on Tirerack which led me to this post.

Any clue the star type was designed with my car in mind or more so for just G80?

[Tommi_Mav]

Originally Posted by ssandman

Any clue the star type was designed with my car in mind or more so for just G80?

If you can't find any PS4S* as OEM in any other model than G80/82, then you got your answer.

IMHO, if you are going to use the M3/4 or even M2 tyre dimensions on your car, you can use the PS4S* or PSS* versions.

[johnung]

Originally Posted by therealm3

So I will be the first to admit with every modern BMW I have owned in the last 15 years I could not wait to junk the oe tires. Mostly cause they were run flats and I wanted PS2's, PSS's and now PS4S's. Yes, I am a huge fan of Michelin tires. Anyhow, I have always wondered if star spec tires would be any different and what that would mean. Well low and behold I stumbled on to this video on you tube and I must say, I hope those star spec 4S tires come in a few more sizes and something that may fit on a current or future car of mine , not just a g80/2. And it makes me want to spend some time digging through tire rack to see what other star spec (non run flat) gems maybe hiding in the litany of choices.

Thoughts?

After watching the video comparing MPS4S to BMW Star rated MPS4S, I would not put that MPS4S Star tire on my daily driver. I have MPS4S on my daily now. I love how great they are in the wet. It's one of the great features of the MPS4S that I would never give up. When I get stuck far from home in a downpour I want the safest tire in the wet for my family.

So it appears that the Star version is optimized to be a dry surface track tire. Maybe it might be suited for a weekend car that is never taken out if there is a threat of rain.

One thing that wasn't specifically addressed in the video is that are sometimes multiple versions of a tire with the same size listed on the sidewall that actually have different dimensions.

This was the case with one size of MPS4S that I was looking at where TireRack actually sells three versions of the exact same size. I dug into TireRack's Specs tab for each tire searching for any differences. One version had a much different tread width than the other two. And choosing one tread width over the other can result in much different handling.

There have been recent articles that discuss the relationship between tread width and wheel width. Their conclusions boil down to the handling will be best if the tread width of a tire is the same as or within a half of an inch less than the width of the wheel that it is mounted on.

Most people assume that they should just buy the widest wheels that they can fit. Not so! It actually may be best to choose the tire that will be run first. Then use its actual dimensions including tread width to choose the optimal wheel width for the tires.

For example a buddy was considering new wheels and the wheel model that he liked came in 8.0", 8.5" and 9.0" wheel widths. (with offsets that would work) The gut reaction would be to go with the widest width, the 9.0". Wider is always better, right? Wrong!

He looked closer at the Michelin Pilot Sport 4S tires that he wanted to buy. In the size that he wanted, the tread width was 8.3". So the ideal wheel width for the best handling combination was actually the 8.5" wide wheel rather than the 9.0" wheel.

Hope this helps!

[Ennoch]

Originally Posted by johnung

After watching the video comparing MPS4S to BMW Star rated MPS4S, I would not put that MPS4S Star tire on my daily driver. I have MPS4S on my daily now. I love how great they are in the wet. It's one of the great features of the MPS4S that I would never give up. When I get stuck far from home in a downpour I want the safest tire in the wet for my family.

So it appears that the Star version is optimized to be a dry surface track tire. Maybe it might be suited for a weekend car that is never taken out if there is a threat of rain.

I reckon that the standard PS4S has plenty of performance to give up in the rain to create the PS4S*. I am the same in that to me wet weather performance is a key criteria, and when I looked at that video decided that aside from the * marking benefit I thought the * would be a worse tyre. However, having had plenty of wet weather to try the PS4S in over the last ten days of having them I would say that they offer greater performance than I would ever be willing to utilise on a public road in the wet and thus I'd give up a touch of that wet weather performance in exchange for sharper dry handling.

[johnung]

Originally Posted by Ennoch

I reckon that the standard PS4S has plenty of performance to give up in the rain to create the PS4S*. I am the same in that to me wet weather performance is a key criteria, and when I looked at that video decided that aside from the * marking benefit I thought the * would be a worse tyre. However, having had plenty of wet weather to try the PS4S in over the last ten days of having them I would say that they offer greater performance than I would ever be willing to utilise on a public road in the wet and thus I'd give up a touch of that wet weather performance in exchange for sharper dry handling.

It's just a difference in philosophy. No wrong or right. Some people will say that it's dry most of the time so they want the absolute best tire in dry conditions.

I personally always consider the best and worst case scenarios. If I'm driving in pouring down rain at night (which I have been with my non-Star MPS4S's) then I want the tire that's going to best prevent me from sliding off the road or into an accident or to help me to take action to avoid an accident. The MPS4S wet road handling ability has saved my ass a few times so I wouldn't be willing to give that up.

[quakerroatmeal]

I personally believe the biggest factor is knowing how to drive in different weather conditions. Countless times I've seen people speed or drive crazy fast in pouring rain / inclement weather.

[Desertnate]

Originally Posted by quakerroatmeal

I personally believe the biggest factor is knowing how to drive in different weather conditions. Countless times I've seen people speed or drive crazy fast in pouring rain / inclement weather.

Very true and this thought can be applied to multiple areas.

"This car is terrible in snow... This car is terrible in rain... These tires are terrible..."

While some are objectively better than others in some areas, driving appropriately for the conditions often will go a long way to getting you to our destination safely regardless of the equipment.

[ggrcrash]

Technically, I think that this tire data matters to .0002% of drivers out there, they are the only ones whom actually push their cars to the absolute limit of handling anyway. To put it bluntly, most drivers don't even engage the cars ABS system during regular driving. I would probably accurately guess most of you have actually engaged the traction control less than 5 times, much less than the ABS system, most likely less than even that. Most adults, usually drive like adults...meaning they don't drive 6/10ths of the cars handling potential...Especially a daily driver, that they paid 50k plus for. Not wishing to bash anyone here, but if you drive like a idiot, on the regular, you deserve the tickets for reckless driving or worse.

[1bad14-F30]

Originally Posted by ggrcrash

Technically, I think that this tire data matters to .0002% of drivers out there, they are the only ones whom actually push their cars to the absolute limit of handling anyway. To put it bluntly, most drivers don't even engage the cars ABS system during regular driving. I would probably accurately guess most of you have actually engaged the traction control less than 5 times, much less than the ABS system, most likely less than even that. Most adults, usually drive like adults...meaning they don't drive 6/10ths of the cars handling potential...Especially a daily driver, that they paid 50k plus for. Not wishing to bash anyone here, but if you drive like a idiot, on the regular, you deserve the tickets for reckless driving or worse.

LOL, I think you're on the wrong page bud...

[J555]

Originally Posted by Ennoch

I reckon that the standard PS4S has plenty of performance to give up in the rain to create the PS4S*. I am the same in that to me wet weather performance is a key criteria, and when I looked at that video decided that aside from the * marking benefit I thought the * would be a worse tyre. However, having had plenty of wet weather to try the PS4S in over the last ten days of having them I would say that they offer greater performance than I would ever be willing to utilise on a public road in the wet and thus I'd give up a touch of that wet weather performance in exchange for sharper dry handling.

First of all, I don't think PS4S are THAT great in the wet, but that's not relevant here. With the last tire change, I decided to try the Ferrari spec of PS4S, as they are available in my tire size.

It is quite interesting to see, how different the PS4S are in the manufacturer-specific version. I am not aware of anybody, who compared them in a serious way. In Europe, tires are rated between A (the best) and E (the worst) for fuel efficiency, wet performance, and external noise. While the specified noise is the same for all, the efficiency/wet performance of the PS4S in my size differs:
- standard version: efficiency: C, wet: A
- AMG version: efficiency: D, wet: B
- Porsche version: efficiency: D, wet: B
- Ferrari versions: efficiency: C, wet: B

Back to the difference between the standard version and my Ferrari (K1) one - the tread pattern is different (not a huge difference, but immediately obvious), the compound seems to be softer, too. While they are designed to be improved in the dry, I don't think the difference is significant for me. However, I can confirm they really are worse in the wet. In weak rain, there is not much of a difference. But once hit with a thunderstorm and a lot of water in the street, the front tires can lose their grip with such ease, and minimal transition, which surprised me (even when I expected different behavior).

My conclusion is the same as before - I consider Michelin (and other manufacturers) know very well, what they are doing, and the standard version should be the best for mixed conditions, safe driving, and tread wear. For those, who rarely (if at all) see the rain, the specific versions optimized for dry performance (as AMG) might be worth a look.

[J555]

Originally Posted by J555

Back to the difference between the standard version and my Ferrari (K1) one - the tread pattern is different (not a huge difference, but immediately obvious), the compound seems to be softer, too. While they are designed to be improved in the dry, I don't think the difference is significant for me. However, I can confirm they really are worse in the wet. In weak rain, there is not much of a difference. But once hit with a thunderstorm and a lot of water in the street, the front tires can lose their grip with such ease, and minimal transition, which surprised me (even when I expected different behavior).

A quick update for those who might be interested in this topic...

I was very disappointed with the K1 version of PS4S in front - amazing dry grip and braking, but sluggish turn-in, poor steering feedback, and bad wet performance. While I was about to ditch the PS4S for good, decided to make one more attempt. Hence I bought a fresh N0 (Porsche) version...

To make the long story short, the Porsche spec really is (again) different and clearly superior to the Ferrari. The subjective handling is significantly improved (sharper turn-in, a lot better steering feedback), and the wet performance is much better, too. Not only that, even the comfort is improved, and the rim protector is beefier on Porsche spec. The only drawback I've found so far is the Porsche spec is noisier at low speeds.