Hi,

I was reading the specs for Autolite APP764 plugs, the type that my '99 F150 4.6L call for at sparkplugs.com From their site:

Autolite Double Platinum delivers peak engine performance with virtually no gap erosion. It does this with platinum to platinum firing tips on both the ground and center electrodes. Originally designed for Distributorless ignition systems(DIS), any car can benefit from the long life high performance features as well as the top fuel efficiency over the extended life of this plug. Resistor plugs minimize electronic interference and can aid in reducing electrode erosion. Copper core aids in cooling and improves resistance to fouling. Power tip or extended electrode plugs project the firing tip into the combustion chamber which not only aids in cooling but also cleaning so that fouling is reduced at low RPM.
Half threaded shell was designed for automated installation at the time of engine assembly. The half thread plugs are duplicates of the full thread plugs in every other aspect, they both protrude the same amount into the combustion chamber.

Notice the last two sentences. Has anyone known that there were different thread lenghts? If you go to Advance Auto and look at the pictures of the Autolites vs other manufactures some appear to have a different number of threads.

Not quite sure what to think now? Am I missing something? Maybe I should go with double platinum AC/Delco 41810. It appears to have full length threads which I would assume would provide greater "staying power" in these aluminum heads.

Gearing up for a plug change in about 9 thousand miles. Also I only have 41,000 miles now. Planning on changing at 50k. Not so much because of the miles, but because they will have been in the engine for around 10 years.

____________________________
'99 F150 XLT Sport Extended Cab

 

Here is picture of the cutaway of a head with both types of plugs. it appears on both plug types the threads in the head will always be FULLY "threaded"

http://www.autolite.com/pdf/Half_FullThread.pdf

So I guess it is irelavant which type is used.

 

Obviously from that post, you have not been around long enough to know what plug to go with for the modern Ford Modualr motor.

I can sum it up in 1 word: MOTORCRAFT!

If I were to sum it up in 3 words it would be:

MOTORCRATF!
MOTORCRAFT!
MOTORCRAFT!

I think I have made my point. LMAO! Look at the sticker under your hood. It says MOTORCRAFT!

And, you are in the RIGHT mind set about changing plugs out at at least 50k miles. Good thinking!

Good Luck!

 

yes I am her for an education... lol

Motorcraft AGSF32FM are available from AA. They don't show up when you display the plugs got my model year. But if you search for the part nbr they are available.

Regards

 

I am a beliver now when I got my 99 I did not belong to this site and dropped a set of autolites in ran like crap switcher to bosch platniums it ran like crap I finally changed to the motorcraft platnium fine wire and it runs pretty good except for the plugged cats and bad o2 sensors (completly diffrent prob but the info on this site is invaluable and the consensus is usually motorcraft everything

 

So if I were to change my plugs tomorrow there is no super aftermarket plug, I should just go with the motorcraft, this is the general concensus here? Same with the wires?

 

YOU GOT IT!

Except you don't have wires. You have COP's. Also, be sure to use plenty of dielectric grease in the boots and around where they seat on the plug. You will be taking it back apart if you don't.

Good Luck!

 

I agree