Having seen on this and other MB boards how MB owners love to worry about engine oils I feel I must contribute this. I hate to be the harbenger of 'bad' news but in 45 years of driving, having taken many many cars and a couple of Diesel trucks well over 150-200K miles in the States and other countries (I spent 20 years over seas in and out of about 85 countries) there really isn't much difference in oils in general.

Certainly if I had a new MB that required synthetic oil I would probably use it, but on average most any name brand oil that is API approved will work. I run all my cars and trucks 10k miles between changes. I use whatever oil hyappens to be on special, I mix blends, I don't use additives, and I make sure that the engine gets hot and stays that way for 15 minutes or so when I drive. This is not difficult in S. Texas since most deives are over 10-15 miles long.

To back this up I can boast that in all these years I have never, ever not only not lost an engine to oil related problems but I have never even had an oil related problem. I don't drive new cars, most of mine are over 10 years old, and I don't pamper them.

I would say that your concern about mixing oils is unfounded. I am sure that some oil company 'techie' will advise you to change the oil immediately and pray to the god of OPEC that all goes well, but in reality you stand very little chance of harming your engine by mixing oils.

Now, I am sure that there are many out there that can relate horror stories about mixing oils but in 61 years I have never ever actually met anyone that has lost an engine because of this. Does 'urban legend' come to mind?