Just hit 60k on my 14’ with 10k of that towing my 6k camper. I know Ford says 100k plug change interval, but does that change with towing? Gearing up for another 3k mile road trip and wonder if I should go ahead and swap them out.

 

Total waste of money to swap. These plugs are good for at least 100,000 miles...actually many, many more.

 

Much like oil threads, this topic is also debatable.

I changed mine short of 70k, I bought used around 64k.

Some have commented that tuners suggest changing even stock motors at less than 60,000.

I guess do what makes you happiest. Mine looked great when they were removed. Others looked great too of the pictures I've seen.

I think the V8 motor has less talk about early change intervals, the eco's seem to benefit though, if you believe the internet. My idle was pretty darn smooth, however it did smooth out after plugs were changed. I didn't think it needed to be any smoother.

It does not run any better and I still get 14mpg around town.

Off topic and less debatable but you should consider transmission fluid change around now.

 

I didn’t even think about tuning having an effect, truck has been custom tuned since about 20k.

as for transmission, I did my first fluid/filter change at 30k and just did again including the transfer case.

 

If you are a diy guy, pull one or two and examine. If you are a shop guy? Plugs don't generally 'fail' and leave you stranded. They slowly perform worse. Do you have any reason to think they need changed? 3k mile trip is not much, maybe a fresh oil change if you are getting close.

 

Agreed. I had to replace my plugs around 50k but I could feel a little skip at idle and had recently had a pretty bad ecoboost shudder event on the highway, not sure if that may have contributed.

The cost of the iridium plugs sucks but any competent shade tree mechanic can easily change em in under an hour. I think it took me ~40 minutes the first time and part of that was figuring out the damn clip on the coil connector trying not to break it. If you do replace them motorcraft plugs should be gapped correctly out of the box but I still double check them. Remember you should NOT use a normal plug gapping tool - you can damage the iridium electrode prying against it

 

Actually, you SHOULD use a gap setting tool as they grab the base of the ground electrode where puncturing the coating doesn't matter. Banging on the tip of the ground electrode, or using a screwdriver between the two electrodes is what you need to avoid.

Not one single set of platinum or iridium plugs I've installed didn't need gap adjustments to at least two plugs.

The ones on my eco looked decent enough when I swapped them, but you can have damage on the ground electrode in the gap that is hard to see without a magnification.

If you're at 100,000 miles, it's time to replace those spark plug boots as well.

 

Read the "Severe Duty Maintenance Schedule", and the list of things that cause it to be used instead of the normal schedule, in your truck's manual. This is for my trucks:

(click this text)

 

Agreed at least pull a couple at 60,000 and check them. If they look good then you have plugs on the shelf for your 100K change.

 

While I agree on changing them at say 100k - I have seen regular plugs with enough miles on them so that the center electrode was worn down to a rounded nub :-) If it sparks good, it'll run hahah.