i know this has been brought up a million times but what kind of plugs are best for our trucks? i have a 2001 4.0 auto 4x4 4dr with 50000miles on it and dont want to go the 100000 that ford says they can go! are there special plugs we must use

thanx steve

 

I dont know if the SOHC motor has the same igniton stuff as the OHV, but if it does, then use Double Platinum plugs. something with the ignition on the OHV doesnt like regular ones. When in doubt, look at your emission lable. It will tellyou. Then get some motorcraft plugs (or autolite, i believe they are the same). If you want some good ones that will last, just get the DP's anyway. Just my 02

 

i personally have had no luck with the autolites but the motorcrafts worked like a charm. i have a feeling it may have to do something with the fact that mine is the flex-fuel 3.0.

 

I belive that Autolite manufacturers the Motorcraft plugs.

 

It's actually Honeywell, a division of Allied Signal that manufacturers Autolite, and Motorcraft plugs.

Stay with the Motorcraft plugs for your truck. With Ford's EDIS, the plugs in each bank gets opposite polarity spark, and they fire every revolution of the crank, twice as often as a conventional ignition.....

 

As Bob said, the EDIS waste spark ignition system, works the spark plugs TWICE as hard as the old distributor ignition system. So they have to be desinged from the get-go to handle it.
So IMHO, I'd stay with the Motorcraft plug.

To add some FWIW detail to the platinum plug story, the EDIS coil pack only has three coils to fire the six spark plugs on this engine.

While one plug, on one end of the coil, is being fired on it's power stroke, the other plug, on the other end of the same coil, is being fired AGAIN, on it's exhaust stroke.

This other plugs spark polarity is also reversed, such that the spark propagates from the GROUND electrode to the center conductor, thus you need a double platinum plug for that bank of cylinders to minimize gap erosion on those plugs, over the 100K mile service life.

The other bank of cylinders have normal polarity spark, that propagates from the spark plugs CENTER electrode, so that bank only needs single platinum center electrode plugs.

So, to save some money, Ford only installed SINGLE platinum plugs on that bank & DOUBLE platinum on the other bank.

So if you still have the factory OEM set in there, you'll likely find TWO different plug numbers in your engine. from the factory, for those reasons.

The "PP" suffix in the plugs type number, will denote the double platinum electrode plug & the single "P" denotes the patinum center electrode, "single" platinum plug.

The recommendation is to replace the single platinum plugs with the double platinum series.

That way Ford doesn't have to worry about us getting mixed up & putting the wrong plug in the wrong bank, packinging plugs in all sorts of odd numbers of plugs in odd sets, & Ford/MotorCraft, makes a few more bucks off us on the replacement end, while saving some bucks on the factory installation end!!!!

I mean, multiply the cost difference between a single & double platinum plug, times the number of cylinders in that bank, times the number of vehicles Ford makes with the EDIS system, then multiply that by 2 again. for the profit difference they'll make, between selling us a double platinum plug for that bank at replacement time & Ford/Motorcraft will have a tidy sum in their pockets with little sweat!!!!! LOL

So knowing all that, I suppose we could just duplicate what the factory did & save ourselves a dollar or two!!!! LOL

I believe Ford has a new "FineWire" double platinum plug for the 4.0L now & I hear it's getting good reviews.

Just some more things to fit into the platinum plug story!!!!

 

The plugs in both banks from the factory are single platinum. The center electrode has platinum in one bank, the GND electrode has platinum in the other bank.

I have tried the new "fine wire" plainums in my 3.0L FFV, and they run well....

 

I'm using Bosch Platinum 2's and they are great