anavabi

Hi,
Re: 2008 ML350 (90,000 Miles), & 2006 ML500 (125,000 Miles)-
Is there any merit in changing oil/filter before due date for Service A. Service A automatically resets to 20,000 Km (about 12,500 miles) after each oil change. But because of the old age of the engines I thought maybe I should change it earlier.
Any guidance will be appreciated.

chassis

Merit? There is some merit in changing oil more often than the manufacturer recommends. How much merit, and whether it is required or not, are different questions. I change oil at the manufacturer's recommended intervals.

anavabi

Non-related

Just by chance, are you familiar with WSS codes. I have a problem with front passenger seat.

BlackML550

Assuming that your driving conditions are not overly harsh (dust etc) there's plenty of evidence with late model engines that have low piston ring tension for better fuel economy, that changing your oil sooner is a good thing for ring health as well as usual lubrication aspects. I change mine every 5k miles on average which works out to be every 6 months.

Youll find all sorts of views and emotions on this topic.What I know is that the service intervals noted by car manufacturers are designed to minimise service costs in the first three years of ownership to get the new car buyers back for the next model based on low service costs. So they stretch them out to ridiculous levels. Noting that oil loses ots viscosity with miles, the more often you change it the better. But that won't save a stuffed engine.

Good quality MB Spec No. oil, a new quality oil filter every 5-7k miles and there's not much more you can do.

sauerkrautpower

I always change mines at 5k miles. Always use OEM filters. Penzoil Platinum Euro 0w-40 is what I use. Its made out of natural gas and cleans out the internals.

chassis

Do you mean OBD codes read using a scanner tool? Please list the codes you refer to.

anavabi

Thank you for response. Here are the codes:

chassis

Seat belt related. Why do you have this code?

anavabi

I have the infamous SRS warning light on. I've thorougly cleaned the 4 weight sensors, didn't make a difference. The SRS light doesn't go away no matter how many times I try to delete these codes. The codes don't get deleted. So something serious must be wrong.