Just wondering has any one here used AP5144 Autolite Single Platinum Spark Plug in there 4.0 sohc? doing some work on my truck and my buddy is telling me that these will do there job in my truck with no worry. Any one have any input on useing these with no failure. I my self have always run APP5144 Double Platinum Plug.

 

Its been debated numerous times. Many say you need to use the stock replacement nickel style while others say you can run platinum and have worked fine. Im actually waiting for Scott, aka Dixie Bo.. to install his and see how his runs before I make my purchase or what he plans to go with. So to help answer your question I can't really say 100 percent that you can run em and have no problems, but there have been others who haven't had any problems I just havent personally changed mine and went through it yet. As stated before I waiting on Scott but the all his info he got was from a member and ford tech that ran platinum. Hope this helps some.

 

Ford specifies two different plug types due to cost savings. One side (bank) has a platinum tip, the other side has a platinum electrode. That makes the plug a few cents less than a plug that is completely platinum. Your owner's manual should list a single part number. It is for the plug that is completely platinum. It is probably all you would find at a local auto parts store. You wouldn't notice a problem even if you got the plugs reversed from what it originally came with until many miles down the road when your plugs didn't last as long as they should have. Just use the recommended plug in your owner's manual and don't worry about it. My '97 manual calls for a AGSF-22PP for replacements. It originally came with AGSF-22PG and AGSF-22P.

Copied fromhttp://www.explorerforum.com/forums/showthread.php?t=30083

The reason for this , from my research , is that one bank fires the spark from the ground to the center electrode , while the opposite side fires from the center tip to the ground electrode. Spark jumping from the platinum side to the non-plat material reduces wear on the electrode.
So for longevity it is wise to replace with double platinum plugs.

 

x2 rep on that. Cant beat that info

 

you will be fine. there is a guy that I know of running the SP-498 FIne Wire Platinum plug. Thats what Im abut to put in my truck.

https://www.ranger-forums.com/general-technical-electrical-18/my-truck-gonna-love-me-118790/

Here us the guy on TRS running the single plats:

http://www.therangerstation.com/foru...spark+plug+4.0

I pm'd him to find out how they run:

 

yes you can!

 

As described above, each individual coil within a Ranger coil pack fires a pair of plugs with opposite polarities. A Ranger with a coil pack ignition should use either fine wires (1st choice) or double plats (2nd choice) as a replacement for both polarity groups.

If you want a long change interval, don't use conventional single plats unless you can somehow get the OEM type that has the platinum on opposite electrodes AND you know which way to run the polarity. The confusion with these two issues in the field is why the factory doesn't specify conventional single plats as replacements in Rangers w/ coil pack ignition.

Using a double plat plug takes care of the polarity issue by making the plug universal. Fine wires are not as polarity sensitive as conventional single plats, so they can also be run in any cylinder.

If you have a Ford dealer look up the replacement spark plugs for your Ranger, chances are that the part number has been superseded to the superior fine wire plugs (probably with a -FM suffix).

The much thinner center electrode in the fine wire plug requires a lower firing voltage than conventional platinum plugs resulting in:

1) reduced electrode erosion
2) lower misfire rate
3) longer coil pack life
4) longer plug wire life

 

heck yeah i was waiting for you to ring in Bob! so I am fine using the Platinum Fine Wires it sounds like

 

yes you can, i run bosch 4's. as long as its the right plug for it you should be fine.

 

Here is a coil pack schematic for Ford's EDIS:





One other thing to keep in mind with this ignition system, the plugs fire on every revolution of the crank (top of compression, and top of exhaust stroke) twice as often as a conventional ignition system, which fires every two revolutions of the crank (top of compression stroke)

Bosch DOES NOT make the correct plug to run in a Ford product!

 

A set of Motorcraft fine wire platinums that have run 103K miles. They run great! Notice how the GND electrode is eroded on plugs 1,2,3 and the center electrode is eroded on plugs 4,5,6 showing the effect of opposite polarity spark.

1


2


3


4


5


6


7


8


9


10


11


12


13


14

 

Double Platinum:
1


2


3


4



Fine Wire Platinum:
1


2


3


4

 

Excellent posting, Bob! Your pictures tell the story better than words.

 

Thanks Bob!

 

Go stock Motorcraft. That's all that needs to be said.

 

@takeda

From these postings, it looks like the current plugs are SP432 and SP500, the 432 being the Finewire and the 500 being the plat plug.

You said that the Finewires were 1st choice, but I'm guessing at the cost of them wearing out like a more conventional plug, Vs the platinum (sp500) that are rated about 100k miles.