[ofnaman]

I have always liked vavoline. I use a lot of brands of oil, as I am a gm technician, and for the most part they are all good. I have had problems with penzoil (regular, I have not used penzoil synthetic). I would suggest looking up the api specs and comparing them (I think its api, its the little round circle with specs in it). All oil is made from the same base stock, the difference is the additives each company adds. I use chevron at work and berry hinkley supplies it, I have spoken to berry hinkley's head cheese and he informed me that they actually get base stock piped to them and they add the different companies additives at their plant, and then deliver the oil to the company (I know they deal with chevron, texaco, and mobil, I am sure there is other's they deal with. The same is true with gasoline. I lately have been using store brand oil in my personal stuff. The parts store i get it from actually uses vavoline but it's labeled as store brand, and is a lot cheaper.