I'm currently running it in my '99 Crown Vic P71 with a 4.6L V8.
I have used Delvac 1 for many years but I stopped because a) I had to go to the distributor to get it (right down the street but still a pain) and b) the price at this distributor went WAY up in the last couple of years.
I got great UOA with this oil in my Powerstroke diesel. I don't have any gas engine UOA on this oil but it is one of the better ones. Good stuff and now it is easy to get at a reasonable price.
Give it a try. You have nothing to lose.
I would really like to see an oil analysis on your crown vic.
I saw the new truck and SUV oil at walmart today, and I was going to go for it, then I saw the German Castrol, and had to try that.
I have a 98 F150 with the 4.6 SOHC motor.