I have alwasy heard if its GM...go delco...if its Ford go mastercraft...if its Chrysler go Mopar....its worked for me for over 30 years...

 

Mastercraft? Like the boat? I've heard of Motorcraft.

 

Wow every 15k
Not sure I would agree with that.
If that tuner is seeing significant hp numbers from a change that early then maybe.

 

mastercraft/motorcraft.....tomato/tomato what ever LOL

 

I read it on css.net ill see if I can find the thread.

Heres the thread, its not the one I read that in but a few guys state they change theres every 15k miles tuned. Chevycobaltss3 (HPtuner) said to change them every 10k miles if your into boost alot which Im sure most tuned people are. lol This thread has alot of good info.
http://www.cobaltss.net/forums/2-0l-...23/index2.html

 

anyway, i put in the new factory ones, the car does feel better, i checked all the gaps from the old ones and 2 of them were gaped factor and 2 of them were gaped to about .050 so that was an issue, coming home from work, i did some power shifting and im still having the same problem, but when i just drive normal, the car feels much better, they needed to be changed regardless. so now it might just be the heat that is messing with it...

 

Yea, I stick with Delco. Cant really go wrong with em :P

 

I am running the NGK #6509's gapped at .032 with the stage 1. These are one step colder than stock plugs.