That's a single point of reference that you continuously repeat. Quit parroting someone you saw on the Internet and do your own research. Kent sometimes takes things a little far and helps spread paranoia that isn't warranted.

Right! There is absolutely no reason for any of us to be changing out the oil “often”. 3,000 miles is too short. But if it’s a year on conventional oil, then it’s probably OK to go that short. With today’s oil technology and low sulphur diesel fuel causing less contaminants, engine oils can last longer. And this has been this way in the past 10 years.

Kent is in the business of selling products. He sells how to videos and publications that cater to the unknowing folks. This video does create paranoia and it serves him well in selling products. Even if it’s just a small percentage of the Mercedes community who actually buys stuff from his website.
In looking at his products, he has a diesel purge and oil filter kit for $84, maintenance log book for $9 and $17, another diesel service kit includes oil filters for $76, twin pack oil filters for $30. On demand video on how to change your oil for $3 and another for the w115 for $7. Oil filter housing nuts for $6. Dig more you’ll probably get more oil change related products.

Bottom line is 3,000 mile oil changes are a waste of resources and money. In some cases changing it “often” can actually cause more wear to vital parts versus if you don’t change it often. The reasoning behind this is that the new oil’s detergents are washing off the old oil's antiwear additives embedded on the surface of a wearing part. During this washing off phase is where the most engine part wear happens because the new oil's antiwear additives have not been fully embedded. It is not until the detergents have been depleted that antiwear additives start to work. So the idea is to have less detergent cycles with less frequent oil changes, but only change the oil when the TBN levels are low and soot levels are high.

If you really want to know the optimal oil service interval. Send a sample of your oil to have it analyzed to a lab like Blackstone or Polaris.


.