I used to use Valvoline in my car any time I wasn't using the farm fleet oil. Why did I quit? Honestly it was from talking to Valvoline's tech line on two or three different occasions. I had just bought a SAAB, which specified 10,000 mile OCIs under "normal" conditions, which I fit as perfectly as possible at that time. When I asked them about 10,000 mile drains (their bottles said the 3/3 thing on them at the time), they said there's no way any manufacturer would warranty an engine on 10,000 mile drains! They also said there was no way they'd use their oil for that long, even their synthetic. Was that Official Valvoline Policy or just goober techs talking out their ears? I don't know, but I decided at that point that I wasn't a Valvoline user any more.