I was actually thinking about this when i read the post by the fellow who paid $90 for a tank of 100 octane fuel. I've owned 2 1967's, and neither one of them had a problem drinking 93 (or 92, when I drove into Pennsylvania). Its all a matter of timing. For both of my '67's, I drove them for a while with a distributor clamp wrench in the door compartment, and if I heard them ping, I would retard the timing a bit. Of course, this requires an initial setting that's a bit advanced, and a little guess and checking. But its really the only way to set time on cars of this vintage. In fact, I have a '68 volvo who's shop manual specifically calls this procedure out. It also says to drive at about 30-40 mph in top gear up a moderate hill, accelerate, and listen for pinging ("pinking" they call it...bloody Europeans!) The only time I run any sort of lead additive is in this same volvo, and only when I'm rallying it...Unless anyone here drives their Imperial that hard, I wouldn't worry about adding anything to the fuel. > > I own a 67 Crown convertible > > Does anyone know if adding a lead additive (into a > full tank of gas) everyother fill up or or once in a > while is helpfull or beneficial for the engine and > or performance?? Is it good--or is it just a waste? > > I always use premium grade (and go to different > gas > > stations) > > THANKYOU > > ANTHONY BUNGARO > >