This is copied off an Amsoil site proving that Benz only specifies synthetic
<<<<<<Mercedes-Benz should be commended for specifying synthetic lubricants for their superior performance and for extending drains to minimize the adverse effects of used motor oil in the environment. As time goes on, there will be an increasing number of companies who will do the same. But that won't happen if the oil industry can help it. They are actively working to keep the status quo, promoting many more oil changes than necessary, wasting precious resources, and creating the need to dispose of more pollutants in form of used motor oil.>>>>>>>>
The Benz sludge/wear/issue/lawsuit is because customers installed cheap mineral based oil on a system/engine designed for synthetic...probably group IV/European spec.
The oil change monitor uses algorithms only.......it doesn't know when the owner installs the wrong oil. The dealers were at fault as well using cheapo bulk oil and this resulted in lawsuit.
There was an issue with Brake fluid years ago in the US causing issues in the Benz cars with brake system seals. When the Benz techs(USA)contacted overseas techs with the issue..... the first question asked by the German techs was............you guys are changing your customers brake fluid annually aren't you? The US tech response was............ummmm......what.....you guys change brake fluid in Europe every year!!! The US techs also didn't read the tech manual which did stipulate the brake fluid change interval.......go figure!!
Well...the Germans had to change the brake seal technology to deal with older brake fluid rather than stipulate annual brake fluid changes for the Americans who don't know any better. They assumed everyone did what they did....change brake fluid often/yearly. The German Brake fluid is also been improved longer drain intervals now days.
By the way.......I change my brake fluid every two years with Synthetic brake fluid. I could use the lifetime stuff which I did in the past......but salt corrosion ate through my break line causing me to bleed out the fluid. I use the cheap store bought synthetic dot 4 for now every two years.
The Moral of the story is that information doesn't always transfer overseas when it should...or incorrect assumptions are made leading to issues like above. However......all this proves is that top synthetic oil group IV/V is best!! The information/misinformation also finally does 'catch up' and resolve itself.
Now you might be interested how I know this story.........Well....I used to work for a Mercedes dealer.
I also used to be rep for many car dealers/shops in both selling and training of Diagnostic automotive equipment. Ever hear of Sun Electric or Snap on Tools? That was me!