I just swapped my NGK TR6 plugs out after a year with the turbo on.
They look like I'm running slightly rich, which does not surprise me.
The gap opened up about .005" from the install til now, about .04" now.
I did pull a plug here and there just to check how she was running at various points last year but never checked the gap again.
They were at .035" when I installed them.
What kind of effect on power output would the gap being smaller or larger have on a boosted motor running from 5-10psi?
I have heard the reson for the .035" gapping is to limit the possiblity of the spark being blown out.
I'll report back on any difference I notice on my ride home tonight.

 

you got it with the spark blow out. i think that is the only reason to lower the gap. i run about .025.

i found out this year that even at .025 you can still blow out the spark and the fix for that is to increase the dwell time of the coils. you just start charging them sooner and longer and the spark gets hotter and will prevent spark blow out. the down side is reduced coil life so you dont want to go too much dwell, just enough to prevent blow out.

 

Yup, blow out. You might actually notice better throttle response with the larger gap or smoother running in low/no boost driving.
It also helps reduce EGT's and detonation.

 

Thanks for the feedback guys.
It seems like the new plugs gapped at .035" made my truck idle a little smoother and accelerate or respond a little quicker.
It could all just be in my head too.
The real reason I went to change my plugs other than the fact that they have been in the truck a year, is a very noticleable drop off in gas mileage.
I'm getting about 15-16mpg and was geiing about 17-19 depending on how much freeway and city. It probably is just the cold weather but it didn't really drop off until mid to late December and its been kind of warm for winter here the last couple of weeks so who knows.
No more rambling I'm done.

 

motors don't use spark plugs (engines do thou).

I still cant figure out why my gas milage sucks...my dad has an 02 x cab 2wd 5.3L and he gets 50 gallons more on a tank. I wonder if its my exhaust and throttle body spacer? the knn is susposed to increase milage I thought? Oh, hes got a toneau cover too, so that could help some.

 

I think your right foot may be heavier than your dad's!!