Tyre pressures PS4S

[///Msports180]

Hi guys,

Only had my M3 for a short while and noticed on the last service invoice a note saying recommend to run 40psi. On the tyre plaque is says 33psi? I have the PS4S on it, should I run them at 40 or 33? Currently on 40psi cold.

Thanks!

[AUSf22]

Give 36psi cold a try, it is summer so tyres will heat up which will fluctuate the pressure and temps quite a bit.

[omega2733]

Run them at stock suggestion, 40psi is insanely over inflated that's usually the maximum listed on the sidewall of the tire. You can change pressures for different effects and fine tune handling/grip.

[bloke79]

Yeah - I run about 32 cold, works out to be 36-38 hot.

I ran my last set of tyres at the recommended pressures and found the wore unevenly (middle of the tyre) so were probably over-inflated when hot.

Cheers,
matt

[omega2733]

Originally Posted by bloke79

Yeah - I run about 32 cold, works out to be 36-38 hot.

I ran my last set of tyres at the recommended pressures and found the wore unevenly (middle of the tyre) so were probably over-inflated when hot.

Cheers,
matt

I've found 32PSI hot is the best for performance driving on this tire for me. Day to day though I run 30-32 cold like you depending on outside temp and driving. Anything 34psi or over hot gets really greasy on this tire (if the tread has significant heat) IMO.

[YKIGI]

Originally Posted by omega2733

I've found 32PSI hot is the best for performance driving on this tire for me. Day to day though I run 30-32 cold like you depending on outside temp and driving. Anything 34psi or over hot gets really greasy on this tire (if the tread has significant heat) IMO.

I agree. I run 32 lbs cold for daily driving and it seems to be great

[///Msports180]

Thanks guys. I'll drop them down. It didn't seem right but with the wifes A45 AMG we actually run 42psi rear (235/30/19) as they wear the inside edge bad at stock pressure so I wasn't sure if it was for a similar reason.

[SE7EN335]

Im running 265/35/19 and 295/35/19 Michelin PS4S and the best tyre pressures i find to work for me is 35psi cold front and 34 psi cold rear. It kind of levels out the slight increase in understeer that I feel when I have everything at 33psi cold. Plus the car feels more solid and not as unsettled when going over bumps and imperfections

[PWR///M]

To be honest on my old A45 i also ran it 40psi+ cold and i found the wear was better for day to day driving. Like my PSS ran for ages on that car, lasted like almost 50k with 2 track events. I've been running mine around the same on the M3C even though on the comp 20inch rims i still think the wear is not too bad. I just find running them 35psi is too soft and probably will speed up the wear day to day. Maybe just experiment and find the best for you?

[///Msports180]

Originally Posted by PWR///M

To be honest on my old A45 i also ran it 40psi+ cold and i found the wear was better for day to day driving. Like my PSS ran for ages on that car, lasted like almost 50k with 2 track events. I've been running mine around the same on the M3C even though on the comp 20inch rims i still think the wear is not too bad. I just find running them 35psi is too soft and probably will speed up the wear day to day. Maybe just experiment and find the best for you?

50k on a set on the A45 is alright, we are lucky to get 25k!

I am going to experiment a little bit and see how it goes, try and find a balance as the roads we mainly travel are not the best.

[TopJimmy]

Originally Posted by ///Msports180

Hi guys,

Only had my M3 for a short while and noticed on the last service invoice a note saying recommend to run 40psi. On the tyre plaque is says 33psi? I have the PS4S on it, should I run them at 40 or 33? Currently on 40psi cold.

Thanks!

If you're on stock wheels and tire sizes stick with stock recommended 32PSI. Forget the increased "highway pressures" that may show in your owners manual. If you're on fat rear wheels try 30PSI so you don't wear out the middle of your treads. These are for normal daily use and normal alignment.

The pressure must be set at cold morning temps. I prefer to inflate to 35 on the way home and next morning go deflate to desired pressures.

[mynameisplayer]

"lucky to get 25k!"
Daaaaaaamn. Just hit 25k, my sets have bee PSS, 4S, Cup2, Cup2, and now Cup2 connect (soon)

[///Msports180]

Originally Posted by mynameisplayer

"lucky to get 25k!"
Daaaaaaamn. Just hit 25k, my sets have bee PSS, 4S, Cup2, Cup2, and now Cup2 connect (soon)

That's on my wife's A45, i haven't had my M3 long enough to go through a set, give it time haha.

[PWR///M]

Originally Posted by ///Msports180

That's on my wife's A45, i haven't had my M3 long enough to go through a set, give it time haha.

Hahaha... Good old AMG and their bullshit wheel alignments from facotry. To be fair, they gave me contisportcontact5p when i first had the A45 and they lasted like 20k Like i said, dunno if its some factory bullshit alignment. I ended up going back to my old routine of alignment every 10k and it ended up fine and lasted me ages. M3C wise, i mean i've been driving on the 40psi cold for awhile now and its been fine for me day to day. I do drop them down if i intend on going abit of "spirit drives"... Anyways, would be keen to hear how you test day to day and what you decide to go with in the end.

[White340]

31 cold for me. 32 is recommended but 31 just seems so much more comfortable. Idk how anyone runs 35 or higher. You must feel every crack in the road. These cars are super sensitive for every psi.

[///Msports180]

Originally Posted by PWR///M

Hahaha... Good old AMG and their bullshit wheel alignments from facotry. To be fair, they gave me contisportcontact5p when i first had the A45 and they lasted like 20k Like i said, dunno if its some factory bullshit alignment. I ended up going back to my old routine of alignment every 10k and it ended up fine and lasted me ages. M3C wise, i mean i've been driving on the 40psi cold for awhile now and its been fine for me day to day. I do drop them down if i intend on going abit of "spirit drives"... Anyways, would be keen to hear how you test day to day and what you decide to go with in the end.

There is a lot of dynamic movement in the back of the A45 causing a lot of toe change chewing the tyres out i reckon, and yes shite house alignment.

I've gone to 35psi cold, quite a few spirited drives and seems like a good pressure, going to try 32psi once double demerits are over and see what thats like. Extremely impressed with these tyre's i will getting some for the A45.

[ellipsis212]

Damn it Randy this is a performance car! 100psi minimum

[ECHO]

I was running 32 psi cold as the door inflation label recommends that pressure, but was reading a note written by the mechanic on a recent service report from BMW which said to run the tyre pressures at 40 psi. (Which they had corrected in the service)

I don’t mind the higher pressure for daily driving but am watching wear as I feel that the centre will wear down quicker at this pressure.

Agree with the comments on the AMG steering geometry and alignment - I ran a CLA45 for several years and was constantly changing rubber. The camber and toe-in was extreme but you could throw it around!

[waterbottle1]

Originally Posted by mynameisplayer

"lucky to get 25k!"
Daaaaaaamn. Just hit 25k, my sets have bee PSS, 4S, Cup2, Cup2, and now Cup2 connect (soon)

hey mate, how you find the cup2 vs the ps4s in your opinion? (sorry OP)
overall opinion? (wear,grip,hot,cold etc)
i got pss for last 6000km and never grips.

[///Msports180]

Originally Posted by ECHO

I was running 32 psi cold as the door inflation label recommends that pressure, but was reading a note written by the mechanic on a recent service report from BMW which said to run the tyre pressures at 40 psi. (Which they had corrected in the service)

I don’t mind the higher pressure for daily driving but am watching wear as I feel that the centre will wear down quicker at this pressure.

Agree with the comments on the AMG steering geometry and alignment - I ran a CLA45 for several years and was constantly changing rubber. The camber and toe-in was extreme but you could throw it around!

Interesting that it was also recommended to run 40psi.

After a spirited drive on the wkend i have noticed a little movment in the rear, im wondering if its the sidewall deflecting or it may even be the ESP clamping a rear brake to keep it in line. This is on 35psi cold.

You can certainly chuck the A45 around! Awesome little rockets.

Originally Posted by waterbottle1

hey mate, how you find the cup2 vs the ps4s in your opinion? (sorry OP)
overall opinion? (wear,grip,hot,cold etc)
i got pss for last 6000km and never grips.

I'm also interested, thinking of getting some on a second set of rims for the track.