Check your manual - I think premium is required in all recent MBs. If it is required do not switch to regular, but you could try a different brand if you want to placate them.
I've had good results with Techron, so far as fuel injector cleaners go. Get the strongest stuff, but don't put it in until your last tank before an oil change, it will dump upper engine stuff into the oil. The weaker stuff can be used between changes.
I've had good results with Techron, so far as fuel injector cleaners go. Get the strongest stuff, but don't put it in until your last tank before an oil change, it will dump upper engine stuff into the oil. The weaker stuff can be used between changes.