Jorn, check the Owner's Manual for recommended oil change intervals. Every 7,500 miles is a good rule-of-thumb ... even for older MB engines that used mineral oil. With newer engines using synthetic oil you will see recommended change intervals at 10,000 to 12,000 miles because they run cleaner and the oil doesn't get contaminated as quickly.

Jiffy Lube and oil change franchises will recommend 3,000 mile oil changes because that increases their business, but that's overkill in my opinion. If you check/maintain the oil level regularly and follow the Owner's Manual oil change intervals you should be fine.

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Fred Hoelzle