The FSS in these cars monitors the engine oil's condition, driving conditions, running time between changes and all factors which dictate the interval between services. That is what it is there for.

Use the recommended synthetic oil, and follow the FSS and you will be fine. Ignore the dealer's recommendation for more frequent services, that is just their way of maximizing profits, period, and I'd bet they'd never recommend this if the zone manager from M-B was in earshot.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz