If you want to know more about the design features of MB engines, subscribe to the Star magzine if you don't already. This is the MB Club of America magazine.
Also there was a good reply here, that should apply to everything you read, whether it's on MBshop or elsewhere. Don't believe everything you read, especially if I wrote it.
'01 C Class, Six Speed
'84 Euro 240D, manual, 533K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in