I bought 5 bottles of the cd-2 high performance oil boost at $1.33 a piece and added 1 to my 93 Crown Vic. The car is running 5 quarts 5w30 conventional Maxlife (SM rated) and a Carquest oil filter. It seems like it's a good product judging by the threads I've read about it. Anyone else here use it? My plan is to add one bottle of it to my car every oil change.