Switched from Cup 2 MO1 OEM AMG tires recently to new set of PS4S and noticed PS4S have a bit more road noise in the form of a very light "rumbling" at certain highway speeds. Around town they're quiet.

Anyone else notice a bit of a more "rumbling" when you had a new set of PS4S? 🤔

Running stock sizes 255-35-19 fronts and 285-30-20 rears using recommended pressures on door (42psi front/39psi rear) and can't go any lower or these wheels will buckle.

 

I've noticed the opposite. PSS's to PS4's are quieter for me.

 

PS4S is def a little louder on the highways. Around dallas atleast, the higways are mostly concrete and the noise from the tires is def higher than one would expect from such a high end car combined with such high end tires. but i guess blame the 19inch rims?!

 

I'd tend to agree, although I have a different model, I do recall them being a bit louder when they were new...it's been a few years and I'm due pretty soon for new rubber, which I will replace with the same Michelin.

 

You shouldn’t be surprised going from simi slick soft tires to a harder tires.

 

Can't really say I've observed that. A new set of PS4S is nice and quiet on the roads here. They do get louder once they are worn. My rears are pretty much done and I noticed the other day that I'm getting more noise from the rears at the moment. The fronts still have a lot of tread left. However, I don't have a comparison to the Cup 2, and I don't drive around with high pressures like that. You definitely don't have an optimal contact patch this way. I drive around with the recommended 33f/32r normal load pressure. Yes, I did slightly bend the lip of two of my wheels driving over some raised pavement in the dusk, but I blame myself for driving while getting used to my contact lenses. Otherwise I think the issue is way overblown, unless you drive on the worst roads ever.

 

Quite surprised actually as Cup 2's have that reputation of being too noisy. Then again the MO1's are slightly different.

32/33 mate I wish I could run those pressures but you're running the gauntlet. Put it this way if you hit one good pothole you're done.
I know because I'm on my 3rd set of these "RXC" wheels aka blocks of butter which cost $5000 for a set. I love these wheels though but can't keep worrying about pot holes so it's pressures up ☝

 

Such potholes don't really exist around here, or at least not where I'm driving. Highways are smooth. Some side roads may have potholes, but at 25-35mph they don't destroy wheels and I simply drive around them. Such potholes would probably destroy many other low profile wheels. When I bent mine, it only bent the lip. The wheel itself wasn't bent. They simply straightened the lip and I had to replace the bubbled tire. First time I ever bubbled a tire, so this was completely out of the ordinary. I filed a claim with the California Department of Transportation, and they paid for the repair. I have hit some other stuff on the road, but these wheels are holding up fine unless you drive into something that's more like a sinkhole than a pothole.

 

I have Michelin PS4S stock, and my recommended pressure on the door jamb ar 44 psi front, 45 psi rear. Is that right?

 

Nah way too high for rear. Coupe?

This is the updated tire pressures for Coupe in Australia. We have very bad roads here. If you have sh*t roads, use these pressures if yours is a Coupe to avoid ruining your wheels.

44 psi front
39 psi rear

 

I run stock size PS4S, 35.6 front left, 35.2 front right (because this tire gets a lot hotter than the other side) and 33.2 for the back tires. I live in LA so with the warm weather these tires heat up quickly and will reach pressures of 40-41 front and 37-38 rear and car rides and handles great. My car originally came with Cup 2s from the factory and the car got noticeably quieter and more comfortable going to PS4S.

I went PS4S 295 rear after the Cup 2s and never liked how the car handled after that, it did improve grip slightly in launch control but wasn't worth the change in handling and 295+ tires in the rear look too big and bulky from the rear. Stock size PS4S feels and looks very good and traction is still noticeably better than the OEM PSS.

 

Right, that's the other thing. The pressures we are talking about here are cold pressures. Once the tires have warmed up, even here in the SF Bay Area, my pressures are closer to 40 psi on a summer day and above 40 psi driving hard in the canyons, and during the winter with colder temps the compound gets harder which also gives additional protection. It's summer performance tires for me all year around.

 

I run the GLC at 31psi all the way around. I have sidewall damaged 4 tires so far but my wheels still seem fine. It still won't stick even at 31psi so when I am hunting, I drop down to 21 psi and drive around slowly until I get a bite.

 

Hello, I have a Wagon model with other measurements, but I'll tell you what happened to me.

My car had PSS with MO1 and it worked perfectly and I decided to change to PS4s without MO1, they were XL (with reinforcement). The car worked fine, but at high speeds (+180 km/h) it started to vibrate and the higher the speed, the stronger the vibration. I thought it was a bad assembly and the wheels were rebalanced and the car was paralleled (with the official mercedes dimensions). I went out to test it and exactly the same, vibrations.There was only one thing left to rule out, the tires.

I contacted Michelin and made a formal complaint. They called me a few days later and I told them everything again. Again I received a call from Michelin and this time it was from a person working in the Quality department. He told me that an AMG must mount tires with MO1 homologation, since they are the ones tested by AMG and tested for that vehicle in all possible conditions. He gave me a very clear example, that I could buy again PSS without MO1 homologation and that with total certainty in some circumstances the tire would not work as it should and however an MO1 would.

Whether it is true or not, I do not know, but I bought a new PSS MO1 and the car no longer vibrates.

Now I have bought the wheels that you have, those of the coupe (app-tech) and I see that in that size with homologation MO1 there are only Cup2. When I go to mount them I have clear that it will be a tire with MO1 and maybe increase or reduce a little tire size to be MO1 (PSS, PS4s or Cup2).

 

Man I think I read your post on motor-talk? I was searching for this on the German forums. Seems like MO1 spec is what should be fitted for us sensitive ears type.

I recently came from Cup 2 MO1 after using them for a year and they were a lot quieter than the generic PS4S.
I must complement PS4S for it's cold traction on take off, even with a tune shy of 600hp I can pull in 2nd gear with ESC on Sport and only minimal chirp.

Until PS4S release MO1 in stock sizes for C63 Coupe I may go back to PSS MO1 just like another member on here did. We'll see.

What tires are you on now? Still the generic PS4S?

 

hey man,

quick follow up on this, it seems like you live in Australia as well,

I have recently took the tyres off my wheels cos ive upgraded to Vossens,

Went to get some track tyres for the stock amg rims and what do you know,

2 wheels are buckled and these are the sedan amg rims! not the coupe ones that you have,

I live in Adelaide and the roads are terrible as well but would expect them to be stronger than that...

I also ran 40psi all round (cold)

 

Hello,

I now have the 245/35 R19 93Y size and rear 265/35 R19 96Y with PSS MO1, the generic PS4s I returned them to the dealer.

But the problem that PSS MO1 with measures 255/35R19 and 285/30R20 I can not find them and do not exist or on the website of Michelin, only Cup2.

EDIT: I haven't mounted your rims yet, I have them in storage.

EDIT 2: Links to Michelin

PSS and Cup2 in 285 with MO1
https://www.michelin.es/auto/browse-tyres/by-dimension/285/30/20/99/(Y)

PSS 255 without MO1 only Cup2:
https://www.michelin.es/auto/browse-tyres/by-dimension/255/35/19/96/(Y)

 

I have a hard time believing that it was an MO vs non-MO issue, but rather you might have had bad luck and got a bad tire from the factory. That sometimes happens. The manufacturer specs do tweak tires to specific aspects for the car. Often that's differences in compound to emphasize or de-emphasize an aspect of the regular variant. For example the BMW Star rated PS4S is closer to the Cup 2 with the compounds to increase dry grip at the expense of less wet grip than the regular PS4S, and it has a sharper steering response. I'm also saying this because the AMG Driving Academy uses Conti tires at their events for the most part. They have a partnership with Conti, and the current EXTREMECONTACT SPORT is not an MO tire, at least not in the coupe sizes. If the PS4S comes out as MO/MO1 with the coupe sizes I will certainly start using them, but I actually kinda wanna give the BMW Star rated one a go, if it's gonna be available in the needed sizes. BMW is using it for the first time on the new M3/4.

 

as a quick note - more modern vehicles are sensitive to pitch sequence and harmonics of the tires, as the tire can excite some natural frequencies of vehicles that have lighter suspensions / chassis.

typically, OE homologated tires are also designed / produced to minimize any effect of harmonics that could excite vehicle frequencies.

you won't get this on non-homologated tires.

 

Hello,

In Spain, which is where I live, there is the RACE driving school at the Jarama circuit.

This school has an agreement with BMW to give the courses and with goodyear for the tires.

I discussed my tire problem with them, and they indicated that Michelin was right, and they in their M3 and M4 have had to recode the DTC (because the cars were malfunctioning) to be able to mount goodyear because it is their sponsor.

I think homologation does a lot, especially on high performance cars, on a normal car with no sporting aspirations there is no problem.

 

I'm in no way saying that homologation doesn't do anything, especially with high performance tires. I've argued this before with others and as shown in the video above, there can be real differences in compound make up etc. I'm not denying that. And I can also agree that perhaps on certain lighter cars you could get undesirable oscillations. However, I've done non-homologated tires on several of my performance cars and never had issues. In the past I had to because the OE tire got discontinued for example. I've mostly stayed with Michelin tires. For example on one of my past cars I had to replaced the OE PS2 with the PSS, because the PS2 got discontinued and the PSS was a noticeably step up. I've done similar things with my previous car (Audi RS5) which came with RO1 (Audi RS) P Zero tires, and I replaced them with the PSS and then PS4S. Each tire was better than the previous one, and the same is the case with the PS4S over the PSS in my coupe. I don't notice vibrations at least at the lower 100+ mph speeds that I can do on deserted canyon roads. Car actually feels better than it did on the PSS. Much better road communication and feel. I did drive my C63 in Germany all the way up to 180 mph, but that was on the OE PSS. I didn't have it up to that speed on the PS4S, but to me the PSS didn't feel all that great on this car. I'm not a fan of whatever the difference of the MO1 PSS are over the standard PSS. The PSS felt better on my previous cars than it did on the C63.

So, it's just that your experience doesn't line up with mine, and this is the first time I'm hearing of vibration problems with the PS4S on an AMG. I do still hope they come out with the MO PS4S in the sizes I need. It is the OE tire for other AMGs now like the E63, so they do make homologated versions just not in the sizes yet I need.

 

Does it really make a difference for everyday driving? I've had my first set of PS4S for a couple of years, they're doing just fine. Maybe someone tracking the car would want the OE PS4S rubber?

 

No vibrations at all with the PS4S. I like them a little better than the MO1 Cup 2s that originally came on the car.

 

Hello,

Well, in Spain we are several owners with problems with tires without MO1 homologation (Michelin, Continental, Yokohama and Goodyear).
The same thing happens to all of us, whether in coupe, sedan or wagon, vibrations at speeds above 180 km / h and in some cases notice as if the car "floats".

I used the PS4s (about 2000 km) were going phenomenal, but day by day. I use the car for night trips and my speeds are high and those vibrations I do not accept them, because they do not give me security.
In addition, after returning my PS4s to the supplier, they came to Michelin to see if it was a manufacturing defect and I was informed that the tires were perfectly fine. Michelin took care of the price difference between PS4s and PSS MO1. Michelin customer service 10 out of 10.

As we have discussed previously, for the measure 255/35R19 and 285/30R20 only exist in Michelin with MO1 the Cup2 model and it is not a tire designed for everyday use.

 

Just curious, but what tire pressures are you using, specifically are you using the pressures for normal load (lower pressures) or higher load (higher pressures)? At 180 km/h, that's still below the speed cutoff where AMG recommends the higher pressures. This just sounds very fishy to me, because the tire pressure can vary so much on these cars depending on what you set it to. They have about an equal influence as the tire itself. Then add humidity, ambient temperature and elevation, and you have an additional set of variables that can influence the performance of the tires.