So...if this was necessary every 30,000 miles, how could 2011f150js go that long without plugs?

There are a LOT of folks out there with more than 80,000 miles on their factory plugs without issue. Not everyone goes that long, but to declare this necessary for everyone seems a bit over the top to me.

 

We gap all of our plugs at .030. For heavily modded vehicles we will move the gap to .028. We've seem new and driven vehicles alike come in with gaps ranging from .028 to .056. Gap is quite diverse given the condition of vehicle and how hard they've been driven. All of our plugs come out at 30K intervals. Could we go a bit further sure, but a quick change keeps the vehicle running in top notch shape. The owners manual saying 100k is a stretch but I know many will use that as the measuring stick.

 

Plug tip erosion is dependent on varying factors in every engine.
How it is driven, the compression ratio, pressure rise from turbo charging,
plug tip metal composition, spark intensity, heat range and other factors.
It does not hurt to change more often to keep performance at near top.
As for reducing tip gap it may help ignition and keep the plug in play somewhat longer as a benefit.
Erosion of the tip requires increased spark from the coil to fire reliably under increased cylinder pressures.
The voltage at which the spark occurs is dependent on cylinder pressures and mixture richness.
These vary continuously while driving.
The reduced gap may have an effect on idle quality.
The 100,000 mile mark is mainly a sales pitch that uses plugs made with much harder metals that resist tip and ground strap erosion much better at the 100k mark .
They cost more and in some engines are harder to get to.
Each time a spark occurs a little metal is lost. It's a normal action due to the high temperatures of just the spark it'self then add combustion temps to it.
Good luck.

Goodmluck.

 

Just curious, what brand and type plug do you use or recommend?

 

Motorcraft sp534.... that has had the best results over the years.