I was told If you change your plugs to the spark plug PZT-1-FF4 on your 2005 5.4 V8 It would increase your power And MPG..?? has anyone done this change..?? If so what was the improvement..?? Thanks, Doug

 

I don't see how sparkplugs can increase mpg or power as long as your emissions are still good.

I did hear some rumors from another forum that Ford replaced the standard stock plugs with a different part number (maybe the one you listed) for some reason. Dunno if that was to address rough idling instead...

 

There is a fellow on here that has or had some magic spark plugs. He claimed 100 additional horsepower with them. I think he goes by 73Mach1. Good Luck!

 

Ford does have a message for tech's to replace the spark plugs with the new part number due to a misfire issue, but you are not going to be able to take it to a dealership and ask them just to replace them, there has to be a proble first. Most of your newer 2005's have the new plugs in them already.

 

yes i have them 112hp plugs made by roush.
the new plugs are the same as the new mustangs they were changed when i had the s/c installed cant remember if he said it was a hoter or colder plug. have u seen what the new style plugs look like?

 

 

Well, spit it out man? What is the new part number for the plugs?????