Originally Posted by nemosdad

There is minimal carbon build up in the thread area. There is zero build up on the insulator. There is zero degredation on the firing contact area's. That plug in the picture has never been fired. Or if it has been fired, it's been with no fuel. Either that or the plug has .ooooo1 miles on it. No isnulator has ever looked that clean on a used plug.
If yours have that clean of an insulator, you're not burning anything in the combustion chamber.

Originally Posted by Joewee3.5

My plugs are 1 step colder than stock and I could write my name on my bumper after 150 miles of driving. I wrote it off to catless pipes.

Originally Posted by nemosdad

There is minimal carbon build up in the thread area. There is zero build up on the insulator. There is zero degredation on the firing contact area's. That plug in the picture has never been fired. Or if it has been fired, it's been with no fuel. Either that or the plug has .ooooo1 miles on it. No isnulator has ever looked that clean on a used plug.
If yours have that clean of an insulator, you're not burning anything in the combustion chamber.

Originally Posted by Centexguy

I'm telling you, mine look like that and I don't have soot on my fender or any problems with not burning fuel. I get good mileage, truck doesn't stutter, has good manners, idles smooth.

Originally Posted by borjeb

Perfect, I've been driving on the 5star 87 tune and it feels like what people have been saying with the higher power tunes. When you roll into the throttle at low rpm and it gives quite a bit of boost it stutters a bit. I imagine that's what people are referring to.

Originally Posted by Brianstemm

This is exactly what I'm expiriencing with my 93 pert/tow tune. But only after its been in for a few miles....when first installed, it runs very strong. When I roll on the throttle, the power comes on in incremental spurts. Hard to describe but I think I know what you're talking about.