Quick question about plugs. My friend has an 07 F150 with the 4.6 in it. He just changed plugs to the E3 diamond fire and loves them. I was thinking about them for my 07 GT but that application is not listed on there website but the F150 is. So the question is will the plugs from an 07 F150 4.6 fit the 07 4.6 mustang motor seeing as it is the same. Oh and I just did some quick cross reference and Ford racing uses the same part number for the F150 plugs and the mustang plugs so thus they must be the same. Also has anyone used these plugs and what are the results??????

 

I was watching Horsepower TV about two weeks ago on a Saturday morning and they were doing a DYNO test on some popular spark plugs. I don't remember the details of what the car or it's modifications were (Thinking it was a stock older camaro or firebird??), but they stated that these were the best plugs they tested and they showed an increase of nearly 5 HP when they DYNO'd the car with them installed (most other plugs were 1-2 HP). I went to summit racing's website and was able to locate a part number for these for the 4.6L/281. Looks like it is ETP-E3-54. $5.99 each...... Someone here with access to a DYNO should give these a try and let us all know. I plan to buy these when I change my plugs in the future (Only have 12xxx on my 06 now). GOOD LUCK.

 

I tried them on my last car...sorry...they are just plugs.

There are numerous threads out there...but most of the "tests" you see are with 500hp race motors...and they get 2-3hp. I will take a proven plug maker and design over 1hp anyday.

I will admit their marketing is not as sleazy as some of the other $20 a plug companies. But, we seem to go through this every year...Spitfire was the first...

I really did give them an honest try, but when I saw no change I went back to NGK.

 

Honestly, I think they are pointless/useless. They may be cheaper than the normal replacements like Brisk or the new Champion 1 piece, but it seems to me that spark plug designs have been nothing but hype and no substance. As mentioned above, Splitfire was the first plug with the 'wow' factor, and they were a disappointment.