So I was changing plugs not so much that I thought I needed them, just checking gap and condition. Saw a couple was that was beat up so I decided if pulling to look might as well change them. Glad I did. MPG has been down but new intercooler ,change of seasons etc thought no big deal. I have 34,000 on new sp 534@.030.... On the plugs I pulled they were beat up pretty good, @.035+ gap on all of them and one the insulator around the tip was eroded and chipped. Otherwise the color was good if a little hot/lean ...whitish tan light brown color, no oil etc. Started to have a very light stutter that only I could feel during light part throttle acceleration.
New plug sp-542 @.028 going in, will report after I take for ride , get gas and wash car....