W210 FSS is playing games with me
 

Does the FSS interval change itself according to the driving condition.

I changed the engine oil and installed a fleece filter on the E320 and reset the indicator. It showed me service A in 9900 miles, (little insight is that the previous oil change tech did not shove the filter fully onto the stalk and also crushed it, it was a paper filter.

Since then I have driven it 5000 miles, and had to add 1 qt at 3000 miles, when I added the 1qt the service indicator started to show service A in 8900 miles instead of the 7000 it was showing earlier.

Does the system actually scan the oil?

Yes, it knows that you added a quart of oil and adjusted the distance to service accordingly.

It did that on my brother's E320 too....pretty crazy :D

pardon me guys couldn't help from seeing fleece filter mentioned.I was taught to stay away from those filters,as they have bits of cotton stalk, and seed hulls in them.I use Mahnn paper filters

Fleece comes from a sheep, why would there be cotton seeds or stalks in it...makes no sense.

'Fleece' comes from a chemical reactor. It's not a natural fiber but a synthetic one aka polyester. It has much greater surface area hence longer service life.

The oil level sensor in the M112 also measures engine oil quality (probably just conductance) and the ECU adjusts the service cycle accordingly. Beside adding oil stop n go driving will reduce the time to next change and lots of freeway driving will increase it.

Interesting, and also confirms that there should not be any stalks or seeds in it. :)

The twigs, cotton, sticks, seeds etc filled filter was the metal canister filters, this engine uses a stick on which you assemble exposed element onto - think of it like an oil filter without its metal case when you buy it. Just the centre piece and a bunch of O rings in the box.

btw - The highway running explains a lot then. This car spends most of its life on the highway.

To be accurate, freeway driving doesn't literally increase the number of miles until service is required, it reduces it at a much lower rate. For example, a 100 mile highway drive might knock only 50 miles of the distance-to-service count.

ok it must be a certain filter.Might be the 617.951 engine.

No, I'm sorry but you are not correct! An FSS reset adjusts the next service interval to 10K miles by default. If the car is driven almost exclusively on the highway at highway speeds you could be reminded to service it at 20K (the maximum). Most commuters get about 12K-14K which would require it to INCREASE. This is MB factory documentation and is in the Owners Manual.

If you have other MB documentation to the contrary please post it.

This is not my first rodeo and I am correct. Apart from adding oil, FSS does not increase the remaining distance to service. It merely reduces the distance to service at a rate less than the number of miles driven. I.e. it will deduct one mile from the counter for every two miles driven. In this way it will permit up to 20K miles between service, but will never show more than 10K miles remaining. The counter does not increase with use.

If you reread my posts, I did not imply that the display would be incremented but the number of miles until the next oil change will be increased which is what most of us are interested in.

The reason the fleece (polyester) filter is specified for extended drain intervals is due to a whole host of reasons but primarily due to longevity---up to 15 times longer for fleece vs. cellulose according to Mann/Hummel at this link.

https://www.mann-hummel.com/company/upload/doc/HBAAEJwjOMP.pdf

Based on the info here I would use fleece where available even if the drain intervals are not extended. Mark