bighank

See that the 4.0 V6 calls for Platinium Motorcraft SP498 (AGSF24FM) spark plugs. Motorcraft plugs are made by Autolite. Autolite platinium plug AP5143 appears to be identical but is about $1 cheaper per plug.
Does anyone know if these 2 plugs are identical?
Looked around for compatibility and substitution guides but haven't found the specs on these plugs.

petrock

I don't know who makes Motorcraft spark plugs, but it is usually what ever company is the lowest bidder. If the AP5143 is the plug listed on Autolite's web site for your engine, then you should be fine.

T.Richardson

Didn't Motorcraft replace Autolite as Fords auto parts brand?

I didn't think Autolite made parts for Motorcraft.

petrock

Most auto parts companies, including by not limited to Motorcraft, Mopar & Harley Davidson, change parts manufacturers all the time. Its a financial decision. Who ever offers the lowest bidding price wins the contract. It rarely has anything to do with the quality of the parts.

bighank

Looked at both plugs. Construction looks identical. Autolites are BLACK while Motorcraft look like shiny nickel or maybe platinum. Both are supposedly platinum.
Will spend the extra $1 per plug to get the ones which look like platinum.

petrock

Really? Your going to go off of color? Are you serious? Do you put stickers on your ride to make it go faster too?

The black is a coating on the plug. If you scrape it off its “normal” metal underneath. Also, the “platinum” is not the plug housing (the black part of the Autolite plug). It is the electrode inside the plug that is made of platinum (the part sticking out the center of the plug surrounded by ceramic insolation).