Don't mean to sound ignorant but what does the abbreviation (FI) stand for? See it all the time in the threads but don't understand what it is refering to. I thought it meant fuel injected but that is what the 4.6 is since it does not have a carb on it. Just wondering.

 

It means forced induction, aka. supercharger or turbo.

 

and you might also be wondering, NA, means naturally aspirated, or no supercharger, the air is natural, and not forced in