Welcome! Please post a photo of the C300.

Full synthetic?

Yes it is Advanced Full Synthetic

You're fine, especially since you will be changing the oil again soon.

Clean oil is just that. I'm a big fan of Amsoil synthetic.

Thank you chassis and BenzBopper back in the day it was regular or synthetic and there wasn't much to worry about!

Well, it depends. If Mobil 1 ESP 0w-30 oil is approved by M-B for use in your vehicle that's one thing. If it is not -- I would think probably because of the 0w-30 multi viscosity rating -- I would not use it.

So if it were my vehicle I would drain the oil and replace it with the proper oil. And I am not a fan of removing a filter then reinstalling the filter even if just to pour at the oil in it. So I would remove the filter and replace it with a new one so the bulk of the *wrong* or non approved oil has been removed from the engine.

My experience with various cars over the years is if the factory calls for 0w-40 oil, it can also approve of 5w-40 (but not in extreme cold) or even 5w-50 oil. I have never seen a lower high temperature viscosity oil on the approved list of oils to use. No 0w-30, no 5w-30, and so on.

While there are a number of engines that are able to use 0w-30 even 0w-20 oil that M-B specified 0w-40 oil suggests the engine in your vehicle requires that 40 high temperature high sheer viscosity to provide the engine with proper lubrication.

I am not the type of person to gamble a few dollars of oil against a possible major engine problem due to using the wrong oil. In your case consider the cost of a 2nd oil change to address accidentally using the wrong oil as a lesson learned...If you are going to service your own vehicle, and there's nothing wrong with that, you must know the proper procedure and follow it and use the right materials in this case oil.

My sl500, A4 3.0, and my XK8 all use synthetic oil. My 69' Camaro 250c.i.. uses synthetic blend. I change oil at 3500 miles on each ride. If I had a full time race car I'd change the oil every time I'd drive. I'm 66 years old and never had a car fail to oil, or a lack of maintenance. I drove my 1967 Galaxie 320k miles from high school until 1987. I'd could go back in the day and the day before that.

moved to W205 forum...