Dutchmanxtr

A few months back, the Ford dealer changed out the plugs and used the 548's. The spec does call for the gap to be .049-.053. I pulled all the plugs and found the gaps ranging from .052 to .056. That just shows the QC on the plugs is poor and the technician didn't even check them.
I re-gapped to .046
Oh and just fro trivia, done under warranty n/c.

cbr600rx7

I picked up a set of 548s from ford yesterday however I found 8 NGKs IX iridiums 6509s today at a small parts store with a 0.044 gap. I know they are not motorcrafts but NGK has a good reputations and to me iridium>platinum since it's what ford originally put in the truck.

lutter5-0

I'm gonna just assume that these are the original plugs. 2011 5.0 149,000 miles.

Motorcraft
CYFS 12Y

cbr600rx7

I would assume so. I started pulling mine today and with 75,000 on them they measure 0.059-0.063.

Smasher!

I'm about to do mine, as I just rolled 100,000km(approx 62,000miles). Time for some fluid changes and spark plug changes.

Would you guys say to stick with the Ford ones? Or going to the local auto parts store and getting whatever matches is fine?

cbr600rx7

If you look over this thread you will see that the factory plugs are basicly no longer in production. This means you have to go with fords updated plug that is a platinum type or go aftermarket if you want a iridiums like it came with from the factory.

cbr600rx7

I am not happy with the NGK plugs I installed. They are under gapped at around 0.037-0.040 vs the advertised gap of 0.044. The truck seems more sluggish and MPG is down about 7%.

Spiky

So, did you gap them properly or it?

cbr600rx7

Iridium plugs are not supposed to be re gaped because the tip is so delicate and can be damaged easy.

Spiky

Why would you touch the tip?