I got the Sprinter when it was brand new in '06, it came with Mobil 1 0w-40 and that was the recommended motor oil.
The van has a maintenance monitor on it, so it tells you when to change the oil based on how you drive.
The first oil change was at 5,000 miles, then every 10,000 after that, at the dealer at a cost of $120 per oil change.
Now keep in mind being a company vehicle I am not working on it.
The maintenance monitor always came due in the 15k range, I never reset it after the first few oil changes and it was fun to watch it flash negative miles til service and then a clock too after a year had passed.
MB said every 15k or one year, which ever was sooner.
Said that right in the owners manual.
It also said in the manual to use the M1 0w-40.
It held 10 qts, I always took the empty bottle home and drained them into one bottle and had a full complete qt of brand new motor oil for free.
10 "empty" qts drained equaled 1 full quart.

 

Reposting from my other post (flashing oil light part 2):

Spoke to the mechanic. My oil was low (3/4 bottle to fill) , my boyfriend did not read the oil level correctly and it was not full like he told me it was, hence the oil pressure light coming on (note to self, I will check the oil from now on) He said the oil pump was fine.
I'm going to admit that I'm really bad at checking the oil (I know, I know) but I feel if the intake gasket was bad and it was leaking enough oil to be a real problem it would not have gone as long as it did before the light came on.

Thoughts?

 

Being 1 qt low will not cause the oil light to come on.
Being 4 qts low may.
Get in the habit of checking the oil once a week, like every Sat morning before you leave the house for the first time.
I check the oil in both our cars every Sun before church.
It will take you 2 mins to check it, leave a post it note on the dash as a reminder if you need to.
Make sure the oil is between the "ADD" and "FULL" marks.
If you always check it when the engine has sat all night you will always get a accurate reading, just make sure you are parked on level ground.

EDIT:from "ADD" takes 1 qt.

 

Just diagnosed and solved my constant-on oil light on my '01 disco II.

Short version: The wire from the pressure-switch on the engine had worn and made contact with ground, illuminating the lamp in the instrument cluster.

Longer version: The light came on and stayed on immediately after an oil change. However, the oil filter did fill quickly and the engine ran normally, indicating to me that the pump was operational. I did notice that the lamp sometimes would flicker during turns. Back in the garage I found that the light remained on even when I disconnected the pressure switch (just above the oil filter). According to the wiring diagram, this circuit is a simple connection from +12V, through the lamp on the instrument cluster and then through the switch. The switch is "normally closed" meaning that sufficient oil pressure opens the switch and light goes out. So when the light remained on I knew that there was a wiring failure somewhere along the circuit. I got to the intermediate connector behind the steering wheel and measured 121 ohms to ground on the relevant pin. That's probably high since I was using a local ground point and the switch is grounded at the engine block. Apparently the actual resistance is low enough to illuminate the lamp.

Fix: I found where the wire had worn and repaired it. I turned out to be at the attachment point next to the alternator.

 

 

Don't think we will ever know, her last post was 5 years ago about her frame having rusted out. She has not logged in since. Safe to say since it was 2 years after this she learned how to check her oil level and didn't drive it any longer with in 3-4 quarts low. The oil light won't come on for 1 quart low.