hey guys thanks for your responses, I signed up for this forum because I just started a new job at a garage and one of the things we do on the side is lubrications and oil changes.
The mechanic that told me this information is not dumb, he is a well accomplished mechanic that can do every type...
I have talked to many mechanics about motor oil that say that when you start using Pennzoil in a car then you cannot switch to another brand because it will screw up your engine if you do.
Then I move away to another area and the oil change people say that this is just not the case and they have...