I was becoming worried about oil consumption too. I bought the car as pre-owned (53,000 miles) and did not think to check the dipstick oil level right away either. I had to add 4 quarts in the 1st 6000 miles, but I only drove 400 miles between the 3rd and 4th quarts; this is what got my attention.

I was discussing this at my dealer, and one of the seasoned techs told me to drive the car harder - I had been putting around like an old woman. I also performed what a friend called an "Italian tune-up". I added a large bottle of Chevron Techron Concentrate and started running the Hell out of it. Sure enough, it started using less oil.

I just had a "B" service done and now have the new Mobil1 ESP 5W40 229.51 spec oil. So far and after 1100 miles, the car measures the oil level as o.k. I need to pull the dipstick to confirm, and plan to do that today.

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Ich liebe meinen Mercedes Benz!