As far as MB wanting stuff done early. (grumbles) Our new MB service adviser and the follow up quality assurance call from the service department head T'd me off two weeks ago. With insistence that oil and fluids by the book need replacing at a specified time interval, and not simply due to miles driven. Officially you have to. Right. A person has about 1/3 rd of the miles on the vehicle vs odometer count, the car is 3 years old, essentially new, still has new car smell and everything ... and somehow these MB approved fluids now expire / go bad in three years??? I Don't Think So.
Sure it is cautious to replace everything every few years ... but this is not a race car ... and to the tune of $500 - $1000 and more, it is easy to say it has to be done; when they're not paying the $$$$ bill ...
I mean this in all respect, ICERabbit, but you are entirely wrong. It is entirely possible that the oil in your van is fine. It is also possible that it is in desperate need of being replaced, depending on a variety of factors that include temperature, relative humidity, operational load when you are using the vehicle, the condition of the oil filter based on these uses, and other factors.
The bigger issue, though, is the overall condition of your van. Your van, or any car, really, needs to be inspected at least once a year by a person who is familiar specifically with the design and engineering procedures of vehicles made by its manufacturer. Various things can happen over that year that create a safety or operational issue. An improperly secured line carrying fuel or brake fluid or coolant can, for instance, start rubbing against a component and approach a point where it is going to leak. Bolts, screws, and similar things can begin to work loose. Mice, squerils, and other animals get into cars and make messes of various kinds.
You are also going on about it not being a race car. My friend, 104 bhp a liter was very much race car performance levels just a few decades ago! Do you remember Saab’s competitor to the E36 M3? It was called the 9-3 Viggen, and it used a 2.3 turbo four making 230bhp (the M3 made 240, remember), which is 100 bhp liter. These are high precision, high stress engines. They require much more rigorous maintenance than older, simpler, less powerful, larger engines.
I do not dispute that MB dealers charge very impressive amounts of money for relatively simple service, and if you can find a Mercedes-qualified person elsewhere, I get that. But trust me, replace the fluids that are supposed to be replaced at roughly the time or mileage they are supposed to be replaced at. You might find this maintenance expensive, but its gon nothing on the repairs you will end up having down the road from not observing it!