jkob5

tried to make sure I get the PSS instead of dunlops for the tire, but salesman reports it's just a matter of what tire contract they have at the time. O well, PSS eventually regardless.

DZ8222

I'm using the set of pss that came with the car, I notice the traction is not that good too, it does not give me the confidence when cornering, of course I am only comparing to other cars 2008 Porsche Cayman and 2015 Benz E350.
Not to mention it is realy bad on bumpy roads.

RDOCA

What are you running for air pressure front and rear?

DZ8222

That I have no idea, I did not pump it ever since I got the car 3 months ago.
How do I check the air pressure btw?

RDOCA

Of course you should be checking air more often than that but the correct numbers are on the back of the fuel door. For day to day driving it should be 38 front and 33 rear.
On a new car many times the pressures are high and would give a rough ride.
Besides a manual gauge the car has a page on the screen behind the steering wheel to give tire pressure.

DZ8222

Thank you! Let me check and get back to you!

VaserC63S

Well my car is one week old now. 265 miles. It also came with the Dunlops with MO1 marking.. I was also told they were run flats but am going to go check update you exact specs I see on the side wall.

Another curiosity is why are we pumping more air in the front tires than in the rear tires? I have had staggered wheels in my BMWs and I have same size wheels on my Range Rover, but in all cases you pump up the rears a lot higher than the fronts. The Rover is nose heavy by a couple hundred pounds, the BMW is almost even, and this leaves me curious why mercedes does the exact opposite of the other manufacturers with air pressure? What is the reasoning for this?

RDOCA

If I remember correctly the weight distribution is 54% front and 45% rear.

PunjabiM3

Not correct on staggered BMW sizing or for pretty much most sports cars for that matter. My M3's all ran about 37F and 33R. My R8 I run 36F and 34R. The idea is you want more PSI in front for better steering response and road feel; for the rear you want lower PSI for better grip given the car is RWD. Higher PSI on rear will have less traction due to the sidewalls not having as much give.

VaserC63S

Last car I had was 335 with premuim and sports package and the recommendation was more PSI in the back staggard tires just like the Range Rover, but it doesn't count as its an SUV and 4x4. I hear you though. Am loving the car except for the silly gear shifter I hate and the kinda harsh ride. I would prefer it more compliant in comfort and leave the other modes as is. By the way what is this MO1 business? Are we on Run Flats or not. Am confused.

Guilty

Guys,

I go through rear tires a LOT. I'm on my 3rd set at 8k miles.

So far, on this car I had:

- Dunlop Sport - Maxx RT - Total crap. Noisy, handle like ****, and lasted 2000 miles (yes, I drive aggressive with TC off all the time).

- Michelin Pilot Super Sport - Good grip early on, terrible towards the end. Comfortable and pretty quiet. Lasted 4000 miles. 30k warranty.

- Current Tires: Michelin A/S3 Plus. All season tires (even though I live in SoCal). Better grip than PSS, even at low tread. Handling is very close to PSS. Quiet as well. 45k miles warranty.

The A/S3 Plus are underrated since they're not MAX Performance tires. I suggest that more people try them. You won't be disappointed. They also come with a better warranty.

For people that are unfamiliar with the michelin warranty, here's how it works:

1. Call Michelin and open a claim. Takes 5 min.
2. Go to a Michelin dealer for a tire inspection. If you toasted your tires in 5k miles and you have a 45k miles warranty. You get a prorated credit towards the new ones. That's about an 89% discount on your new tires.
3. You pay the remaining portion to the Michelin dealer + mount and balance and they take care of the rest.

Now, the bad news is that for our cars, the mileage warranty is slashed by half since we have a staggered setup. You only get the full 30k or 45k warranty if you can rotate your tires. However, a couple of times, I've been lucky and got the full warranty. Sometimes, the michelin CSR won't notice that you're running a staggered setup and you get full credit.

That's the reason I only buy Michelin. Good tires and great customer service.

msd3075

To check the tire pressure through the gauge screen, press the buttons on the left steering wheel spoke in this order:

Home Button
Up 3 times
OK
Down 1 time
OK

It should display the tire pressures after you've driven the car for about 1/4 mile or so.