The engine management system computer is allegedly able to calculate the condition of the oil and bring up the service indicator whether or not the time frame / mileage flag is reached or not.

It may give you peace of mind to have the oil changed however if you consult your M.B. dealership technical adviser they may advise that this maybe unnneccesary .

I had the same condition as you describe in my CLK - done far less than 7500 miles in a year - no service indication. Dealership advised that change was yet unnecessary.