I had bought a used punto about a week ago. After my initial adventure of driving with hand brake and sorting it out, everything is fine now. I am new to cars and getting confused over engine oil. As i understand i need to use Selenia diesel engine oil. I understand its fully synthentic oil(please clarify this as i keep reading that its semi synthentic). Last service was done at 38k with all filters and oil change. odo is now at 43k. I don't think oil has been topped up. One of my friend checked the oil and since it was black he said to change the engine oil immediately. but manual says it has to be done at 15k. Is it suppose to be black? Also how often should i do the top up and how much? Please advise.