Hello MB Doc,

Thanks for your reply:

There is a maximum mileage that the system will allow for YOUR driving style. You must have reached that maximum.
That happens if you do a lot of around town driving.
The instrument cluster uses imputs other than oil quality & mileage to calcaluate when the next service is needed

Your answer was in reference to my earlier questions:

The last time I decided to do an oil change between intervals in my C 240, the FSS read "8,000 km A Service". After changing the oil, the FSS automatically extended the mileage by 1,600km reading "9,600 A Service".

I decided to do the same this time by chaging the oil betwen intervals. This time, the FSS read "3,200 km B Service". After the oil change, the FSS still read "3,200 km B Service". This time, the FSS did not extend the mileage after the oil change like it did the last time. I thought it was supposed to extend to a new mileage, but it did not this time around.

I did not understand what do you mean by "maximum mileage". Could you plese eleaborate?

Yes, I did a lot of short trips and stop-and-go driving this time around. It's that why it did not automatically extend the mileage even after new oil has been put into the engine?

Thanks,
Johf