ok... I know you guys have gone over this one a zillion times lol
I switched to synthetic mobile one after my first oil change.
Many oil changes later -I'm at about 16k now & im thinking of changing to Red line or Royal Purple.
What'll you guys think is best!
i have to order the redline from a vendor and wait for it everytime i want to change my oil...
If you insist on one or the other, I recommend Redline. A guy on a Mazda 3 forum posted results of several UOAs and one for Royal Purple was not favorable for wear.