While on the earlier subject of oils and filters, I became curious as to favorite and frequency of use for fuel additives.

Here's an interesting thread (long but useful info) on different types, effectiveness, and effects from prolonged use:

http://theoildrop.server101.com/ubb/...5;t=000065;p=1

I've used Marvel Mystery Oil, but lately lean towards Techron. I know some owners (Family Ride) use only premium which has better additives than us regular users which probably requires no off the shelf help.

Interesting note was still the ol' method of water spray into the TB (old farts like me used to pour it into the venturi's) is still used.

 

I tried a bottle of Techron for the first time ever (I've always been skeptical) and noticed around .5 mpg improvement under city driving conditions on my 50K mile 5.4L. We'll see if it holds up.

 

I like to use a fuel addative every 30K, I think I use the silver STP bottle, good stuff, (supposedly) cleans fuel injectors and deposits on the valves and pistons. Water through the throttle body, or manifold vaccum, in small amounts (supposedly) "steam cleans" the pistons. Just keep the fuel filter new every 30K.