one year plus old AMS oil

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May 23, 2004
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.
Yes, there is an oil analysis lab here in the Toronto area. It's in Mississauga and it's called Wearcheck. Their site is
Any oil will darken if it's cleaning other oil deposits or if the car is having some blow-by or other combustion related issue. Amsoil or any other synthetic/dino oil is not magically immune to this. Since you say your engine is "healthy" then I lean towards the clean up. What type of oil did you use before? How many miles total? Which 20W-50? Series 2000? About 4000 miles with some racing and 14 months are beyond Amsoil's recommendation as you state. Please send a sample to Wearcheck.
the engine was rebuilt 2 years ago. It has less than 20,000K on it. I only used AMSOIL since day one. Oil stay clean for firs month or so and then it gets very dark. I have no blowby and after 14 months it has used less than 400ML of oil. My car runs a bit rich due modifications.
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