Hawkeyes81

I was wondering if I can ru the Roush Performance Colder spark plugs in my stock 5.4L?

bubbabud

Why?

techrep

iTrader: (1)

Does he mean Roush ?

Mod (Ret.)

I think so...made the corrections for him.

techrep

iTrader: (1)

Your stock 5.4 3v requires SP515 motorcraft plugs.. unless you have an 08 with up-dated heads then you will need SP509's

nrivera04

If everything is stock, keep the plug stock.

Dirttracker18

If you are running stock or even slightly modified, running a colder plug risks fouling the plugs out.

It may be okay and will not hurt the engine but is doing nothing for performance. A colder plug in and of itself does not increase performance. A colder plug is to help dissipate the heat from the tip of the plug faster in conditions where heat is a problem.

For instance running a turbo or supercharger (thus increasing cylinder pressure and therefore heat), increased piston height or decreased combustion chamber size (again increasing compression and therefore heat), running a high level of timing advance, etc.

650NutKase

They'll foul faster and give you crappy mileage since they wont be able to get hot enough to self clean

Summers22

iTrader: (2)

I like when people try those ever magical plugs in our trucks. E3, Splitfire, Pulstar, Rouch......although, I have had good luck with the whirl-o-spark plugs on my lawn mowers:

SCORGE

That little fan blade is what...10hp per plug?