That 7500 mile interval is probably for ideal driving conditions. Chances are your 190E manual advises a more frequent interval for severe service. I don't follow the 'universal' 3000 mile recommendation. I tend to go more by the type of car and driving I do. For my daily driver '84 Accord I try for between 4000 and 5000 miles - closer to 4000 with mostly city driving or around 5000 with mostly highway use.

On the other hand, my 44 year old Fintail gets little highway driving and her ancient Solex carburetors tend to run rich, especially when using the manual chokes in cooler weather, so I've been changing that oil about every 1500 miles.

The best thing I've found to try and keep to some kind of schedule, is to put a sticker up on the windshield to remind me of the date and miles of my LAST oil change.

Happy Motoring, Mark

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DrDKW