Michelin pilot sport 4s for stock F12 size help

Welp, as you know, sometimes in this wonderful Ferrari world of ours, there are dealers that are of the opinion that no matter what, they will always know better and you as customer should never try to interfere with the order of things - because you are not Ferrari.

Just think about the dealers blabbering on about voiding warranty on the ENTIRE car for installing a Capristo exhaust but with stock cats etc.

 

My dealer has no issue with spring changes on warranty cars so I doubt they would balk at the tire recommendation. They send a lot of email invites and service advertising. They might actually be thankful for the spec selection especially if you up the powertrain warranty during the next annual. Pure profit.

 

FWIW, my dealer confirmed they have no problem ordering and swapping the tires for me.

While they have the car the are also replacing the hardware at the rear mesh vents as a preventative measure to prevent any paint corrosion/ bubbling at my request, provided I pay for the labor. They have been extremely accommodating for me so far.

 

Not saying they have. My dealer lets me get away with quite a few things.

It was more just pointing out that some dealers are incredibly thick and stubborn, not realizing that they will probably lose business rather than gain it. It just boggles the mind how archaic the though process and customer relations of some dealers are.

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Hey Il Co-Pilota
Would you have any recommendation of winter tire pressure for the 265/315 settings from your experience, Factory standard for 255/315 was 2.1 (F) and 2.0(R), mine currently is 2.4 for all, still ESC light lit up a few times during speeding up .

Thanks

 

Try 2.0 for all. 2.4 will definitely affect grip.

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Just normal on road, not any crazy stunt, I will try the 2.0 for all as Il Co-Pilota recommended and let you guys know how it goes.

 

Thanks and will keep you guys posted on how it reacts

 

Let me try and explain this to you again.

The cars computer WILL NOT have any issues with 265/315. By comparison, Ferrari uses 255/305 as OE winter size, not 255/315.
The difference in radius between 255 and 265 is so small, that depending on how you drive the car, or what other brand of tyre you might use, the same difference can be found simply from wear, or slight differences between manufactures. We are talking 3.5 mm.

But as I said, you find the same difference between 265/315 as you find between 255/305. Furthermore, the winter size is the size that put the greatest demand on the ABS and ESC system, so if anything, the 255/315 setup would in theory be the setup that would have an issue, not the 255/305 and 265/315.

 

Perhaps booting 730hp through summer tyres when temps are single digit centigrade has more influence on TC lighting up than any rolling radius discrepancy?

I’m running non-stock tyres on my summer wheels and the tendency for the TC to kick in is no greater or worse than the stock setup.

 

No, it is absolutely not safe to assume - far from it in fact.

It does not work like that. There is a built in margin of discrepancy in the system, there has to be. I have a very close relative who works for Bosch Automotive, and is involved with developing these systems. The car does not know the size of the tyres, only the wheel speed in relation to each other. Depending on your driving style, a set of tyres can easilly be worn so that the front to rear diameter difference becomes smaller. On top of that, tyres vary quite a bit between both models and manufactures.

He said that he experienced ESC interferrence sometimes with a tyre pressure well above what it should be and brand new tyres. Let me explain to you exactly what would happen if the system was triggered due to an issue with the diameter. It would kick in the ABS and you would get the ABS shake in the pedal. Additionally, it will be constant and at constant speeds. If you have that kind of issue it shows up as you drive at steady state speeds, not during an acelleration. Furthermore, these systems are designed to learn as the car drives and wears the tyres. I have seen examples in older systems like in the F430 for example, where a car got new tyres both fron and rear, but where the rears were bald and the fronts almost like new, and the brake pedal was shaking as the car stated to drive on the new OE size shoes. The F430 system is a lot more crude and can't handle much variation, and in some rare cases the car needs to drive a bit to re-learn. An F12 is however, a lot more clever.

Here's the short of it. My Lusso, on stock broken-in winter tyres, with the ESC in WET will light up that light. It has less power and the 4RM system. Yet even with gentle throttle, it sometimes kicks in. These are powerful cars, that's it. New winter tyres take a while to run in, that's just how it is. Add a lot of tyre pressure to that cocktail, and you are losing a lot of grip. You say it's the tiny radius difference that's at fault, but you completely disregard the most obvious reasons why the rears may struggle a bit. 730 hp, cold weather, tyres covered in UV protection which makes them very greasy, rubber that has not been heat cycled, and a pressure which curves the tread patch. And you want to blame the diameter difference which is exaxt same as what Ferrari uses? C'mon.

Let's be a bit blunt. Putting its power down is not exactly the,F12's strong suit on a good day. Now think about the things above and put it into perspective. New shoes, power, loose ass, greasy rubber etc. If you took out two F12's both with new winter tyres, but one with the 255/305 combo and the other with 265/315 combo, I doubt you would feel much of a difference, and I'd bet you anything that the ESC light would come on about the same. Most noticable difference would be a slightly softer ride.

Choose to believe what you will, but remember it's just a personal assumption and what you say is absolutely not safe to assume.

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Hi, how much did they quote you for labor to do this preventative measure? What are they doing to prevent the bubbling?

 

$1900, which I don't mind at all. It's NOT a solution that is directly from Ferrari, but after countless hours of research and consulting with a few friends of mine who are engineers the corrosion/ bubbling seems to be a result of the dissimilar metals (aluminum body panels and studs, and steel mesh/nuts). The paint and clear coat should be enough of an insulator, but I believe the slight vibrations from driving over time can wear it down enough where there is contact between the metals. The contact won't cause it solely but with an electrical connection between the two metals it will. Which would be water.

I am having them replace the steel nuts with aluminum as well as put in nylon washers so there is the slightest gap between the mesh and body. Currently there is hard contact on some of the edges on my car. They will also be applying a spray or grease to the under side that would act as a barrier between the metals, studs and mesh. Still trying determine the exact product that will be best. Car is not going in till Feb 15th.

I think this will suffice to prevent any potential issues. My car is triple layer and I would rather not have to constantly worry about it.

Hope this helps.

 

I thought the 2.4 was too high anyway but that was from my tire guy , I wasn't there when he changed the tire / wheel bal / wheel alignment , and since the improvment from PZERO to PS4S was such dramatic, I went with his settings for a week until I was ready to drive it more aggresiviely . Hence seeking recommendation from Il Co-Pilota.

Updates:

I dropped the tire pressure to 2.1 for all, improved a lot. and Winter weather and cold tire did affect the grip as well, once the tire temp warmed up to 25 C and pressure went up to 2.3 bar, you can feel stronger grip and car dynamics much more stable , ESC didn't kick in once after the dropping of tire pressure.

I will try to be more aggresive today and let you guys know, but so far 2.1 for all has no problem at all.

 

Are you running the MPS4S as winter tyres??? What is the outside temps? I thought you had also gotten a set of actual winter tyres as you said winter tyres.

Anyhow, both the 812 and F12 seems to like about 2.3 as hot pressure. Sounds like you are getting dialed in. Try the 2.0 as suggested as you will find that once tyre temps go up a bit more, the pressure can spike a bit. Basically what you are aiming for, is the correct hot pressure. If you put it at 2.0 you should see around 2.2 driving normally and 2.3 when pushing, and that would be pretty much perfect.




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I'm currently stuck in Shanghai due to covid restrictions , winter here isn't as cold as Canada lol , it's average 6 to 10 C day and 2 to 4 at night .

So I uses PS4S on all my other cars 911 and DB11 as all season tires purpose , sorry for the confusion.

I did some freeway driving today, with the lower tire pressure it definitely give me more grip.

So 2.1 for all at 14 C , which equivalent should be 2.0 for all at around 4 C and 2.3 at 24 C .

 

The best 1900 you can spend. Some people added paint protection on the underside 1mm to separate from the vent.

 

Sad the centigrade and bar specs here have no meaning and too lazy to do the xref. But glad folks are posting their results.

 

I just took a look at the Shanghai wx f/c for the next 10 days. -2c to +8c; mostly dry with some periods of rain (for our US chums, that’s 2 degrees below freezing to 8 degrees above freezing ).

And you’re surprised that a summer UHP tyre loses grip in these temperatures when you light it up?

 

I used to live in bay area in past decades, as long as I don't go to yosemite , all season tires should be ok, now in my experience, shanghai is similar temp all year around as bay area.

There is really no much point to use winter/snow tires in shanghai

 

I used to be the same, only reads F and PSI, but now have be adaptive to local standards otherwise no one would understand me lol...

 

If your in San Jose California then you don't have to adapt. I lived their for many years and left when they stopped speaking my language. Seems odd to need decimal points in Bar when you can just use PSI in whole numbers. I prefer the metric system for fasteners though. It uses single digits instead of fractions.