I wonder if someone can tell me if there is a way of telling if your car has synthetic oil or regular dino oil. The reason I ask is when you take it to a shop
(an honest one I hope) and you don't visualy see them putting the oil in the car, How do I know that he actually used the syntheic? Is there a color difference, or smell, or any other charactoristic that would help me determine he did what I paid for.Thanks