Alarming Tyre Wear on Michelin Pilot 4S 35is

[Ole gits rule]

Is that tyre not losing pressure with splits like that?

How much air were you having to put in when you top it up?

Is this the same corner with the goosed shock?

When my MPS4S’s were fitted the garage put 41 in the rears, it was awful, dropped them down to 36 and a totally different handling car afterwards

Yep, I am 35/36 rear and 33/34 front - 41 seems very high

[baz-j]

Michelin Pilot 4S have the reputation for quite rapid wear. Here, they're worse than worn, they're illegal and dangerous.

Whatever the pressures, the alignment or any other factors, they shouldn't have been allowed to reach this condition. Shame on you, baz-j.

As I said low miles done since mot when they were recorded at 4mm and no indication that there was a problem since - tyre pressures checked at local service station regularly too despite not doing the miles. Covid has meant that car has been sat on the drive going nowhere the vast majority of the time aince MOT. Yes it’s my responsibility to ensure the tyres are safe and yep they are getting replaced immediately. 3mm wear on that number of miles I have not seen before in 25 years of driving.

[baz-j]

Is that tyre not losing pressure with splits like that?

How much air were you having to put in when you top it up?

Is this the same corner with the goosed shock?

When my MPS4S’s were fitted the garage put 41 in the rears, it was awful, dropped them down to 36 and a totally different handling car afterwards

The last visit was a couple of psi topup. The bad shock is near side front, the bad tyre is off side rear.

[baz-j]

Is that tyre not losing pressure with splits like that?

How much air were you having to put in when you top it up?

Is this the same corner with the goosed shock?

When my MPS4S’s were fitted the garage put 41 in the rears, it was awful, dropped them down to 36 and a totally different handling car afterwards

The last visit was a couple of psi topup. The bad shock is near side front, the bad tyre is off side rear.

I was running my tyres on similar pressures to you but changed to be closer to the RFT pressures after a puncture on the Isle of Skye some years ago. The tyre pressure monitor came on within a minute or two of disembarking a small roll-on roll-off ferry coming back from a beautiful place called The Isle of Raasay. The puncture was fairly close to the side wall and I suspect might have happened when disembarking the ferry to do with the ramp which wasn’t exactly shallow.

[Zforbes]

FWIW I run tyre pressures advised by the manufacturer. It may seem high but wide and low profile tyres need to be run at high pressures to have the road contact the tyre was designed to take

If you owned a Audi or Porsche with similar sized & similar branded tyres you would be running significantly lower PSI than Bmw recommend on some of their cars so who's right ?
Also worth noting the Z4 G29 recommend less PSI than on E89 on similar sized rims ,
41 psi in a 255 30 19 on 9j rim no thanks

My mate with a 996 911 C4 runs his rears at 44 because Porsche recommend it in his owners manual

BMW have calculated what pressure your tyres run flat on the road (giving full road contact) based on diameter, width, profile and axle weight, I'm not clever enough to do the sums but I trust BMW are IMO so who am I to argue

Maybe this is due to increased sidewall rigidity of the RFT's that the car was designed for and running non RFT's should be lower maybe -

I don't understand though why people don't trust the recommendations and can only think they believe it i high compared to what you have run in other cars in the past. Running yoo low will cause increased tyre wear and less grip (due to less road contact) and so does running too high.

The difference between 38 and 41 is not significant IMO.

[Busterboo]

Michelin Pilot 4S have the reputation for quite rapid wear. Here, they're worse than worn, they're illegal and dangerous.

Whatever the pressures, the alignment or any other factors, they shouldn't have been allowed to reach this condition. Shame on you, baz-j.

As I said low miles done since mot when they were recorded at 4mm and no indication that there was a problem since - tyre pressures checked at local service station regularly too despite not doing the miles. Covid has meant that car has been sat on the drive going nowhere the vast majority of the time aince MOT. Yes it’s my responsibility to ensure the tyres are safe and yep they are getting replaced immediately. 3mm wear on that number of miles I have not seen before in 25 years of driving.

You're right. I was wrong. I apologise.

[mr wilks]

My mate with a 996 911 C4 runs his rears at 44 because Porsche recommend it in his owners manual

BMW have calculated what pressure your tyres run flat on the road (giving full road contact) based on diameter, width, profile and axle weight, I'm not clever enough to do the sums but I trust BMW are IMO so who am I to argue

The difference between 38 and 41 is not significant IMO.

I only recently sold my 997 Carrera4 so i'm well aware what pressures work ie

Summer and Winter tyres

17 inch and 18 inch wheels :-

Front 29 psi (2.0 bar)
Rear 36 psi (2.5 bar)

19 inch wheels :-

Front 32 psi (2.2 bar)
Rear 36 psi (2.5 bar)

These tyre pressures are valid only for Porsche approved tyres.

or



Tyre Pressure results for : Porsche 911
We have found 1 tyre size that matches your vehicle. Your tyre pressures are as follows :

FRONT TYRE SIZE FRONT TYRE PRESSURE REAR TYRE SIZE REAR TYRE PRESSURE
235/35/R19 Y 91 33 PSI / 2.3 BAR 295/30/R19 Y 100 36 PSI / 2.5 BAR Search for 235/35/R19 Y 91 on TyreShopper
Search for 295/30/R19 Y 100 on TyreShopper

etc etc

& implying that Bmw know best yeah that's why 50% if not more of Z owners on this forum swap the recommended RFT for standard

[mr wilks]

My mate with a 996 911 C4 runs his rears at 44 because Porsche recommend it in his owners manual

BMW have calculated what pressure your tyres run flat on the road (giving full road contact) based on diameter, width, profile and axle weight, I'm not clever enough to do the sums but I trust BMW are IMO so who am I to argue

The difference between 38 and 41 is not significant IMO.

I only recently sold my 997 Carrera4 so i'm well aware what pressures work ie

Summer and Winter tyres

17 inch and 18 inch wheels :-

Front 29 psi (2.0 bar)
Rear 36 psi (2.5 bar)

19 inch wheels :-

Front 32 psi (2.2 bar)
Rear 36 psi (2.5 bar)

These tyre pressures are valid only for Porsche approved tyres.

or



Tyre Pressure results for : Porsche 911
We have found 1 tyre size that matches your vehicle. Your tyre pressures are as follows :

FRONT TYRE SIZE FRONT TYRE PRESSURE REAR TYRE SIZE REAR TYRE PRESSURE
235/35/R19 Y 91 33 PSI / 2.3 BAR 295/30/R19 Y 100 36 PSI / 2.5 BAR Search for 235/35/R19 Y 91 on TyreShopper
Search for 295/30/R19 Y 100 on TyreShopper

etc etc

& implying that Bmw know best yeah that's why 50% if not more of Z owners on this forum swap the recommended RFT for standard .

[flybobbie]

Tyres can be easily damaged, anyone know the M5 flyover near Bristol docks, i drove over the metal expansion joints and it ripped the tread off a Morris Ital tyre.

[baz-j]

Good to see that Kwikfit have a 10% discount on 2 rear Michelin Pilot Sport 4S making a fitted cost of £186 per tyre. It's 15% off for 4 tyres. Offer ends today: https://www.kwik-fit.com/offers/15-off-michelin

Booked in.

[R.E92]

There's £50 off at Costco at the moment when you buy 2 Michelin tyres, £326 at for 2 rears in the standard sizes. That includes fitting, balancing and disposal of old tyres.

[Ole gits rule]

Tyres can be easily damaged, anyone know the M5 flyover near Bristol docks, i drove over the metal expansion joints and it ripped the tread off a Morris Ital tyre.

Morris Ital - a Morris Marina by any other name

I know the road well

[Zforbes]

My mate with a 996 911 C4 runs his rears at 44 because Porsche recommend it in his owners manual

BMW have calculated what pressure your tyres run flat on the road (giving full road contact) based on diameter, width, profile and axle weight, I'm not clever enough to do the sums but I trust BMW are IMO so who am I to argue

The difference between 38 and 41 is not significant IMO.

I only recently sold my 997 Carrera4 so i'm well aware what pressures work ie

Summer and Winter tyres

17 inch and 18 inch wheels :-

Front 29 psi (2.0 bar)
Rear 36 psi (2.5 bar)

19 inch wheels :-

Front 32 psi (2.2 bar)
Rear 36 psi (2.5 bar)

These tyre pressures are valid only for Porsche approved tyres.

or



Tyre Pressure results for : Porsche 911
We have found 1 tyre size that matches your vehicle. Your tyre pressures are as follows :

FRONT TYRE SIZE FRONT TYRE PRESSURE REAR TYRE SIZE REAR TYRE PRESSURE
235/35/R19 Y 91 33 PSI / 2.3 BAR 295/30/R19 Y 100 36 PSI / 2.5 BAR Search for 235/35/R19 Y 91 on TyreShopper
Search for 295/30/R19 Y 100 on TyreShopper

etc etc

& implying that Bmw know best yeah that's why 50% if not more of Z owners on this forum swap the recommended RFT for standard .

997 is a newer car than the 996 not for your benefit being a previous porsche owner, for other readers.

The 996 C4 runs 36 front 44 rear and listed just as a comparison to our zeds 41 rears.

Also, I didn't suggest RFT's are better at all, mine are going as soon as I burn them out, I think they are bloody awful. Most cars lost there spares due to weight removal quite a few years ago, BMW's solution was the RFT whilst other manufacturers chose tyre weld and inflator. Both options have their positives and negatives.

My point was BMW know best on what tyre pressure should be and maybe its 41 because the RFT's are fitted as standard and normal tyres should be different pressures.

So my question back, what are the benefits of running lower pressures?

[mr wilks]

I only recently sold my 997 Carrera4 so i'm well aware what pressures work ie

Summer and Winter tyres

17 inch and 18 inch wheels :-

Front 29 psi (2.0 bar)
Rear 36 psi (2.5 bar)

19 inch wheels :-

Front 32 psi (2.2 bar)
Rear 36 psi (2.5 bar)

These tyre pressures are valid only for Porsche approved tyres.

or



Tyre Pressure results for : Porsche 911
We have found 1 tyre size that matches your vehicle. Your tyre pressures are as follows :

FRONT TYRE SIZE FRONT TYRE PRESSURE REAR TYRE SIZE REAR TYRE PRESSURE
235/35/R19 Y 91 33 PSI / 2.3 BAR 295/30/R19 Y 100 36 PSI / 2.5 BAR Search for 235/35/R19 Y 91 on TyreShopper
Search for 295/30/R19 Y 100 on TyreShopper

etc etc

& implying that Bmw know best yeah that's why 50% if not more of Z owners on this forum swap the recommended RFT for standard .

997 is a newer car than the 996 not for your benefit being a previous porsche owner, for other readers.

The 996 C4 runs 36 front 44 rear and listed just as a comparison to our zeds 41 rears.

Also, I didn't suggest RFT's are better at all, mine are going as soon as I burn them out, I think they are bloody awful. Most cars lost there spares due to weight removal quite a few years ago, BMW's solution was the RFT whilst other manufacturers chose tyre weld and inflator. Both options have their positives and negatives.

My point was BMW know best on what tyre pressure should be and maybe its 41 because the RFT's are fitted as standard and normal tyres should be different pressures.

So my question back, what are the benefits of running lower pressures?

Benefits from my own perspective are a less skittish & more compliant ride plus less likely to get impact damage to rim .
What i have gathered from my forum wheeling time is when it comes to wheel size , wheel fitment , tyre size , tyre brand & tyre pressures there just isn't a definitive answer to what is best in every aspect of the above , just way too many differentials .
Information shared is only a guidance but ultimately the driver / owner has to go with what they feel is best for them .
I do take issue when its suggested Bmw know best but you intend going against that theory by fitting non runflats they either do know best or they don't

[Zforbes]

997 is a newer car than the 996 not for your benefit being a previous porsche owner, for other readers.

The 996 C4 runs 36 front 44 rear and listed just as a comparison to our zeds 41 rears.

Also, I didn't suggest RFT's are better at all, mine are going as soon as I burn them out, I think they are bloody awful. Most cars lost there spares due to weight removal quite a few years ago, BMW's solution was the RFT whilst other manufacturers chose tyre weld and inflator. Both options have their positives and negatives.

My point was BMW know best on what tyre pressure should be and maybe its 41 because the RFT's are fitted as standard and normal tyres should be different pressures.

So my question back, what are the benefits of running lower pressures?

Benefits from my own perspective are a less skittish & more compliant ride plus less likely to get impact damage to rim .
What i have gathered from my forum wheeling time is when it comes to wheel size , wheel fitment , tyre size , tyre brand & tyre pressures there just isn't a definitive answer to what is best in every aspect of the above , just way too many differentials .
Information shared is only a guidance but ultimately the driver / owner has to go with what they feel is best for them .
I do take issue when its suggested Bmw know best but you intend going against that theory by fitting non runflats they either do know best or they don't

Thanks for your thoughts, much appreciated and I will take your comments on board next time I pump my tyres up. Not wanting to start a disagreement, each to their own.

I have always gone with manufacturers guidance on pressures and never had a problem even when I drive with a heavy foot, if anything I've lost grip when pressures are down and not high. I believe people think because it sounds high to cars they've run in the past but they will be because low profile wide tyres do need more pressure to maintain contact on the road which does result in better grip and tyre wear evenness.

I don't agree with the rim damage though neither do I agree with causing wheels to crack even on RFT's. This is a common misconception because they are hard. The only impact RFT's have on wheel cracking is due to the amount of leverage pressure caused when fitting tyres due to the stiff bead. Cracking is caused by damage on the edge of the wheel that creates stress points that start the cracking.

What I'm saying is those running 326m and other prone wheels is keep your eye on the fitters and their tyre levers damaging the edge. If you do get a corner dent dress it out with a needle file to even out the stress propagation point. Not easy with a tyre on but doable if careful.

Also, I haven't said on any of my posts that RFT's are better. 2nd car I've purchased with them on, last one they got ditched and so will my zed when I've burnt them out.