i just got a cls55 this week (black/ash) and i absolutely love it. i have 2 questions though...1. what is the difference between the two airmatic sport modes? and 2. do you really have to wait 1,000 miles to break it in? thanks.

 

Congrats on the new car you're gonna love it...... regarding your questions

1. Ride Height and suspension stiffness

2. There are many who subscribe to the "break it in like you stole it" theory - something which I subscribe to myself. The theory goes that you get one chance at seating hte rings valves, pistons etc, and this is better accomplished with maximum cylinder pressure (i.e. WOT). See Tony's post here break in .

However if you have the 030 package with the LSD you might want to be cautious until after approx 1000 miles and the LSD oil change - several of the SL boys have noted LSD issues when run hard with no break in.

Many others subscribe to the break it in cautiously rule...... and they can chime in here

Personally I have always driven my card hard from the getgo and always had significantly better performance than average for that model.

 

isorryi - IMO Break it in hard, however always give it a couple of minutes, at least, between WOT sessions (10 to 15 seconds long WOT Sessions) for cooling down at normal diving levels. The first 300 to 400 miles is when you have the best opportunity to best seat the piston rings. From there the seating process diminishes because the original honing pattern in the cylinder walls has lost most of it's original aggressive texture, thus reducing it's lapping-in capabilities.

Why does WOT operation produce a better Piston Ring seal? When the Motor is at WOT cylinder pressure is at it's highest levels and because of Piston Ring design and Piston Ring-Land design the Rings are being pressed into the cylinder wall at the highest levels during WOT operation. Therefore, being lapped into the cylinder walls aggressively and conforming to the cylinder walls better producing a higher quality seal and thus reducing the leak down of combustion gases past the rings. When this occurs there is more combustion pressure on top of the piston and therefore more work is performed by each combustion cycle.

Now, I also feel that changing the oil filter and oil (Mobil 1 0W-40 Oil) at around 350 miles, 700 miles and again for the third time at 1,000 miles is important to keep the metallic lapping residue from building up in the oil filter and Motor. As evidence of this Lapping-In Residue, you will see when the oil filter is removed at 350 miles that it is medium gray in color which is a significant color change from the original white color of the filter.

So, as you can see, when you break your CLS55 in hard there are added responsibilities that go along with it to ensure maximum protection of the Motor during the process. Keep in mind, it's not an abusive process but an attentive and respectful process.

030 LSD cars I believe should have the CASTROL SAF-XJ 75W-140 Fully Synthetic Gear Oil changed at 600 Miles, 1200 miles, and a third time at 1,800 miles to reduce the contamination in the gear oil during the LSD break-in process, when using the "Hard Break-in" method for the Motor. The LSD gear oil resides in an unfiltered environment and will benefit as the Motor does from more frequent gear oil changes. BTW, it took some searching to find this MB specified Gear Oil in my area. - Bob

 

Bob,

As a SL65 owner, I am very interested in your LSD comments. Are you a MB Tech? How did you determine the 600, 1200, 1800 diff oil change intervals? If you are going to work the diff hard from the start why not a change at 300 miles? One of our SL65 bretheren blew his diff up by taking his new car directly to the dyno for some full pulls in preperation for some mods that he wanted a baseline for. Isn't the issue more than getting the metal out of the fluid? My understanding is the varried loads on the grears are required for them to seat correctly. I also did not realize that Castrol made the synthetic oil found in our LSD? Is this a substitute for the OEM fluid?

Regards,

Schiz

 

thanks for the replies i really appreciate the info. with the sport modes however i know they adjust the ride height and stiffness but i would like to know whats the difference between sport 1 and sport 2...like which one is stiffer.
as for the break-in process...it seems that it takes work to break it in when you do it hard. i think i might just drive it how ill normally drive the car in the future, maybe a little harder but i dont want to do anything to it if im not going to keep changing the filters like you said...once again thanks for the replies because this is my first AMG (2nd car hehe). any more replies is appreciated.

 

Sport II is the stiffer more sportly of the 2.

 

Schiznick - The Castrol Synthetic SAF-XJ 75W-140 Gear Oil is the recommended MB OEM Gear Oil for the CLS55-030 cars with LSD.

The intervals are arbitrary on my part and were spaced evenly over the MB recommended break-in period for the LSD. The theory being that removing the contaminated oil three times during the break-in period, instead of once, would reduce the abrasive contaminates in the gear oil that can eventually overcome the lubrication ability of the gear oil. When this happens not only do the gears not seat properly but the bearings also can wear abnormally.

Also, the higher pressures developed in the LSD, while breaking it in this way, will introduce more aggressive contaminates into the gear oil, raising the risk of LSD failure. So changing the gear oil more often than recommended will remove most of these more aggressive contaminates, helping the LSD to survive this type of break-in.

Now, this is all base on the conclusion that the type of Motor break-in is more important than the type of LSD break-in. At best it is a roll of the Dice with some effort taken to keep the Gear Oil cleaner than it would have been during the MB OEM recommended break-in method.

As far as what interval to choose, in theory, the more changes the better. However, the law of diminishing returns will come into affect at some point. I chose three changes. - Bob

 

I agree that changing the diff oil 3 times during break in is better than just once.

Mine was changed just once at the recommended 1800mi. The car has 3100 mi now and is still super tight with no problems/noises.