I have an 04 F150 5.4 w/67k. Just changed the OE plugs. While I had it in the garage also cleaned the K&N air filter. Truck runs great but I lost about 3 MPG. I was getting 16 all around and am now getting about 13 under the same conditions. I bought a Purolator air filter and switched it with the K&N but there had been no difference. I used Champion plugs as the replacements. Anybody had any similar results or comments? Truck ran great before and runs great now.

 

You should only use the OEM Motorcraft plugs. You might also want to get some CRC mass airflow sensor cleaner. I used to run a tune-up and carburetor shop and my son ran another tune-up shop, both of us experienced mpg fall-off on Fords with non-OEM plugs.

 

I wouldn't think the brand of spark plugs would make a drop of 3 MPG but you have a lot more experience in that than I do so I'll take your word for it. As far as using Motorcraft spark plugs, my truck will never see another one after the time and expense I incurred in changing the OE plugs. By the time I bought replacement plugs, extraction tools I had close to two hundred bucks in a spark plug change which I think is unacceptable. I know alot of people swear by using OEM parts and I would agree in most applications but I just can't get myself to do it with the plugs in this case. Thank you for your input.

 

the oem replacement plugs are a "1 piece" design....not the shi**y 3 piece ones

 

Actually for a 2004 5.4 engine the plugs are the two piece design. The Champions he replaced them with are the one piece design but I would yank those things out right away as too many people have experienced problems with them in these engines.

 

Unfortunately I don't have a hundred bucks to throw away by replacing the plugs again. Am I being led to believe that everybody that has used Champion plugs as a replacement in these trucks has had some sort of problem? If that's the case and the Motorcraft replacements are still the old two piece design, then it seems there's no suitable solution for replacing the plugs. Can we here from somebody who has had success with Champions? Thanks for all the input on this.

 

Not everyone has problems but many and enough that I would not put them in my truck. The two piece design is fine if you use a small amount of anti seize first on the plug threads. Plus the plugs don't cost hundreds order them from Rock Auto and I think its less then $10 bucks a plug.

 

Let me start by saying I appreciate the input on trying to figure this out. I didn't say they cost hundreds, but I bought them from RockAuto and they were 12 bucks a piece. I just hate to change them again right away. The Motorcraft is 7 and change. Just curious about two things. If the plugs are obviously firing properly why the drop in mileage? The truck runs fine. Also why does anti sieze on the threads keep them from breaking? Since it's the lower part of the plug that gets stuck in the head this is below the threads. Thanks ahead of time.

 

It keeps them from breaking because its the carbon build up that makes them tight in the holes and hard to get out. The anti seize stops that and allows them to come out easier the next time you change them just be sure not to put too much and get it on the ends. This way they come out like they should rather then being torqued too much and then breaking. Also make sure you torque them back to the right amount so they don't blow out after install. Sorry I miss read the post above about the hundreds part.

 

Well I guess I'll have to switch back to the Motorcraft plugs. They will pay for themselves if my mileage goes back up to where it was before the change. In the mean time I'm getting ahold of Champion and see what they have to say, probably a waste of time but I'd like some answers to why I pissed away my hard earned money on their product if it doesn't work any better than that. I'll keep ya all posted.

 

The OE plugs have a different resistance and the COP's coil winding's are optimized for the resistance. Plugs like Bosch , NGK and Champion are not the same resistance. I dont know why? The Ma draw from the COP is much lower with OE plugs and the ECM senses this and the fuel injector pulse width is shortened. The non OE plugs take a higher Ma draw and cycle the injectors longer because the ECM is sensing a high load condition when there is none. This is what I was taught in the early 2000's by a Ford Design Engineer when Ford was pushing 5.4 powered trucks towards us large fleet owners.

 

I don't know why you would have lost mpg by changing your plugs unless there was something else wrong. I had the plugs in my 07 5.4 changed out last year and put in Champions. It's run awsome and I picked up alittle mpg in the process, plus I no longer have to think about those 2 piece plug.

I know some people say only OEM plugs, but mine has run great with the Champions and I see no reason I'd go back to a 2 piece plug any time soon.

 

Well thank you all for your responses. Ford390 - that make's sense but wouldn't there be a problem with every 04 that didn't use OE plugs? hcbph - your truck is an 07 mine is an 04 I don't know if that would make a difference. I'm not done doing my research on this yet - I'm stubborn so I'll keep after it and see if I can find some other answers? I'll keep ya posted. Thanks again.

 

You need to keep in mind these engines are like snow flakes no 2 are alike they all have some quirks that are not the same as other trucks of the same make. some motors are happy with the champions some not
seems odd but true

 

Well I contacted RockAuto and explained my situation. They said they contacted Champion and said "that's unusual" but sorry since you've installed the plugs it's nothing that would be covered by warranty. More corporate america BS! I didn't know the plugs were crap when they were in the box. Years ago I was a warehouse distributor for a few automotive franchises, Champion being one of them. It's amazing how things have changed over the years in favor of marketing and the mighty dollar. I guess if I worked for Walmart or one of their other big customers now they would listen. Well to make a long story short I'm done with both RockAuto and Champion. I'll order, pay for and install some more Motorcraft crap and let you know how I make out! It's enough to drive a man to buy a Chevy. (I didn't really say that).