Who would have thought that a picking a simple spark plug could be so complex???? I posted about a week ago a thread in which I outlined my Autolite spark plug problem. A changed out the old oem plugs for single platinum Autolites, ap5144. Unfortunately they still pinged a little bit, and the advice I got was to only run OEM Motorcraft. Thats cool with me.
So this week I started my search for some good Motorcraft plugs. The part# I got in my last thread, was SP498, a fine wire, single platinum plug. However another person told me to only go with double platinum motorcraft, which is SP440. The confusion begins! While researching the difference between these two, I also found that there is another plug for our trucks, SP412 which is a nickel plug. I guess Ford put three nickel and three platinum in some 4.0 sohcs due to cutting costs or "reverse polarity". (I've read both)
So I drove to my Ford dealership to get this s*** straightened out once and for all. The parts guy, who was the most ornery parts dude I've ever met, gave me the number: AGSF34FP. He priced me at $11 PER plug. I said "Christ Almighty" and walked out the door. UMM where did this number come from , and why are they so expensive...

Can you guys please set the record straight, for me and everybody else that is bound to ask this question in the future.

What is the best OEM motorcraft plug for the 4.0 v6 sohc ?

 

This has been covered before but I guess we'll have to suffer through it again.

The ignition system fires from the ground to the center electrode on one side of the engine.
The system fires from the center electrode to the ground on the opposite side of the engine.
Therefore replacement plugs need to be double platinum to extend the life and performance of the plugs.



I'm not even going into the "search button for noobs" bit .

 

I use the SP432 (platinum finewire) in my 2.5 when I replaced at around 150k. No problems at all. I think I got them for around 5-6 bucks apiece at O'reillys.

From what RockAuto says:

SP498:Finewire Platinum $3.65

AGSF34FP : Suppressor Spark Plug E ENG CODE,PLATINUM FINEWIRE $2.27

I read somewhere where the SP498 are the updated part for AGSF34FP.

 

Ken,

Maybe you didn't get the point of my post. I am new to this forum,but am hardly new to the search function. I have done this search, for hours on end, on every ranger forum out there. Therangerstation, rps, fordrangerforums...etc. There seems to be a difference of opinion on which motorcraft plug is the best. I started this poll to answer that, once and for all. Maybe a "noob" somewhere down the line will look at this thread and have a definitive part number. Then you dont have to suffer through it again, and he wont have to wade through half a dozen different options .

 

I got the point of your post just fine.
The fact is that this question has been asked and answered over and over again.
IF you had bothered to spend time on this site searching , instead of being lazy and wasting our time to spoon feed you the answer , everyone's life would be easier.

I guess the term 'research' is not in your vocabulary.

OH , and have a nice day.

 

Wirelessly posted

S440 is what I put in every ranger that comes into my work. That's all the SOHC get

 

Thanks for the help Dave and Anthony, I'll probably go with #sp440, even though rockauto doesn't carry them.

And Ken, IDK what your deal is, but in the words of Al Gore, "There is no need to get snippy about it" ( I had a great day, thanks) Once again , I have researched and found that even within the motorcraft plugs, there are different options. You said to use double plats. It took me about 30 seconds to find these links, some three pages long, discussing this very topic. Many in these threads said that sp#498 are the recommended plugs.

http://www.rangerpowersports.com/for...A-96405-5.html

https://www.ranger-forums.com/showth...ght=spark+plug

http://www.therangerstation.com/foru...ad.php?t=93130