Having completed my first oil change on my own ... there seems to be more questions from the exercise than I had before getting into it. I change my oil every 3500 miles thro my dealer and my car has 43,000 on the odometer. But since my 36000 mile servicing, I started to get less miles/galon and my suspisions grew as what is happening to my baby. So I took it onto myself to do the oil change, upon constant pushing from my colleague who does his oil change everytime by himself. When I drained my oil it was dark brown and watery (more like mud water). The oil I filled in was Mobil and it was in honey color. I told this to my colleage and told me I may have been running the car with infrequent oil changes ... which I said "NO". He thinks it should not be dark brown but somewhat darker that the honey seen in new oils. Do you guys see something wrong in the color of the oil?