If you went 100K on the OEM plugs with no problems why not stick with OEM plugs? Spark plugs ain't rocket science; they either work properly or they don't. I remember all the hype in the 80's and 90's about platinum plugs, multi-electrode plugs, aircraft engine type plugs, etc. I tried them all and never found a bit of difference on engines that burned unleaded fuel.

 

I just did the plugs on my Wife's 2012 with 90K on it. I went with the OEM Motocraft plugs went in with no problem. A friend that has a repair shop has always told me to go with OEM on anything built after 2008. He states that everything is so optimized at the factory now that you can't really do any better in the aftermarket. Also tolerances and specs are so precise on newer motors that it's not worth the risk using anything else. Just his opinion but I trust it. Good luck.

 

The Ford 2.3L SOHC Lima engine (also known as the Pinto/Lima inline-4, used in vehicles like the Ford Ranger, Mustang, and Mazda B-series trucks from the late 1980s to the late 1990s/early 2000s) featured a dual-plug cylinder head in its later versions, with two spark plugs per cylinder (8 total for the 4-cylinder engine).

This design stemmed from the engine's single overhead cam (SOHC) layout with only two valves per cylinder. In such heads, the large valves occupy much of the combustion chamber space, forcing the single spark plug (in earlier versions) to be positioned off-center on the side. An off-center spark plug causes slower and less uniform flame propagation across the chamber, leading to incomplete combustion, reduced power, higher fuel consumption, and increased emissions.

To address this without switching to a more complex (and expensive) dual overhead cam (DOHC) four-valve-per-cylinder design:

• Ford added a second spark plug on the opposite side of the chamber.
• This created two flame fronts that burned the air-fuel mixture more quickly and completely, improving combustion efficiency, torque (especially low-end), fuel economy, and emissions compliance during stricter regulations in the late 1980s and 1990s.
• It also allowed slightly higher power output (e.g., around 105 hp in dual-plug versions vs. earlier single-plug models).

The ignition system was distributorless (DIS), with dual coil packs firing both plugs in paired cylinders simultaneously (one on compression stroke for useful ignition, the other on exhaust as "wasted spark").

Later Ford/Mazda 2.3L engines (e.g., the DOHC Duratec/MZR family introduced around 2003+) reverted to one plug per cylinder, as the four-valve pentroof chamber allowed a centrally located plug for optimal combustion without needing a second one.

This dual-plug approach was a cost-effective engineering compromise common in some older two-valve engines (similar to designs in Alfa Romeo, Nissan, and certain motorcycle/aircraft engines) to enhance combustion in a less ideal chamber shape.

 

That's nice, but it has absolutely nothing to do with this thread and marks you as a likely spammer.

Good luck.