So my car has had synthetic oil since 100,000kms it now has 158000kms and after 8000kms the oil is coming out a lot darker than when it goes in.To my knowledge after 8000kms it should come out looking pretty close to the same as when it went in.Conventional oil will change color a lot after like 3,4000 kms but synthetic is a lot different. Does anybody know what this could be caused by or has anyone had has similar problems.Obviously if i'm running a little hot or if my breather is getting contaminated it's going to affect the oil but to me my oil seems a little to dirty for the amount of kms i put on between each change. I will have the oil tested but if you guys have any input let me now please.soory for the long post.