branmin

Have an 09 SL550 and it states that the air (cold) should be 30 Front 33 Rear, yet I noticed that the MB dealer had told me previously and had put air in the tires that were around 36/37 at cold? Have around 11000 miles and condition of tires are good as I don't push her... but started to notice increased tire noise at these pressures and not as smooth as they used to be..........So I decided to go with the original recommended pressures and it feels smoother, but when I hit an un-even surface, I feel it more than before.
Interested to hear what pressures some of you are running at and what you would recommend that I should go with at cold? I have 19's Bridgestones(AMG wheel package) and really feel that in say another 5 thousand miles I would like to change to a quieter ride. Anybody also done this and noticed a considerable difference and what did you change to?

Appreciate your help and comments. Thx.

IngenereAMG

These cars are very sensitive to tire pressure. I run 39/40 cold in my SL55.

branmin

what is the recommended pressure by MB on your car............

branmin

40 people already viewed this........need some replies pls before tomorrow, as off to the dealer for a repair and just would appreciate hearing what you run on? Thx so much.

teeth

36/38

mlandis

In terms of MB's recommendation, I'd look at the tire/loading information card on the driver's B pillar, then look at the label on the inside of the gas filler door.

branmin

Agreed, and mine says 30/33?

jagostini

My tire pressure was set at 38 and 39 and I changed it to 30PSI, but the recommended level posted on the door states 27-29. I flet that this give me the flexiability to study this alittle more while being close to specs. The car does ride smooth now, and I did not noticed the tires looking kind-of-flat. I still have not figure out why my tires were over-inflated. I tired to get the info from tireplus.com, but nothing. If you find the info let me know. By the way, I live in Florida, and I thought that a PSI of 38-39 when the tires are cold during the summer time might be too dangerous. So I think part of the answer lies in what part of the country you live.

OC_AMG

I run mine at 40 in the rear and 35 in the front.
19" w/AMG wheels. Otherwise I feel more sidewall wiggle on hard acceleration

branmin

So I am at the dealer today and wanted to know why if MB give a rec of what I have already mentioned, why they are suggesting higher pressures. I was told that the pressures are incorrect and should be getting a sticker with the correct pressures shortly!! Also by having them as stated..30/33 would/could cause the low pressure light to come on????

Totally confused now?

jagostini

He is right, the tire pressure warning light will come on, but you just have to reset the tire pressure monitoring system to the new PSI. The information is in the owners manual. It take 5-minutes, and then you have to drive the car around for about 15-minutes, and the system re-calibrates itself to the new PSI. Many times I feel MB and the service advisers are full of #$%. You read the owner manual, and the car stickers, and you try to make some sense, and nothing matches up becuase the owner manual is written for 5-cars, etc... Have you guys ever noticed that if your passenger does not put their seat belts on, or removes it, you will not hear the seat belt chimes? In the book it states the option works, but depending on what year of month your SL was built, for get it. Just m=one of the many examples.

mlandis

+1. Why would MB put an incorrect tire pressure sticker on thousands of cars? Even if they did, if it were incorrect, why haven't we heard of more tire-related accidents or a recall? Seems to me like the door and gas stickers are all you need here. The service adviser is just trying to make their personal opinion sound like fact.

At least OC_AMG gave you a reason for why someone would want to overinflate the tires! But to say the MB recommends overinflating them? Bollocks.