Hi I have been using AMS oil 20W50 in my semi race VW jetta. I changed my oil about 14 months ago but the car was stored during winter. In total I have put on about 6000 KM normal usage and about 10 solo events. I am still driving on the same oil. The oil looks very dark almost black. Is this normal? I know AMS clamis that I can use the oil for one year but each car is different. My car does not burn oil and has a very healthy 11:1 CR motor. the problem is that oil gets dark and black after 2000 km. I want to send my oil for an analysis but I dont know where to send it and how much it would cost! Are there any oil analysis labs in Toronto Canada? Thanks in advance.