Ya i know.. My previous set of BKR6E lasted about 8k miles with no problems when i replaced them... As for a waranty, i dont kow, and dont honestly care because they are so cheap at $1.87/plug... Had it affected my engine in any bad way other than a misfireI would have cared a lot though.
Now that i look back at the fist pic i posted of all four, i can see one is cracked.. I guess i passed it off as dirt/grease at the time... Geez, i need to pay closer attention to my own ****.

 

Dang, plugs should last a good 30-50k anyway, if not longer. Hell, my expedition they are supposed to last to 100k, and its got 90k and still runs great, never changed the plugs yet.

well, at least you found the problem. -1 for NGK plugs.

 

Everything ive ever read about copper plugs says they should be replacedoften, andat least every 10k miles for our engine's (1.8t). Plat is a different story for sure. They should last about 100k miles and then some.

 

Cool, I dont have much knowledge on plugs for these cars yet. Is there a platinum plug that works well for our cars?

 

I put in platinum when i first got my car and had no complaints. But when i read up on copper plugs and tried them, i noticed smoother idle for one, but the most noticeable thing was how much smoother it was in high rpm's and also quicker startup. The plats i used were NGK PFR6Q. Ive always been an NGK fan and i wont let my cracked plug experience ruin that because i may have had them torqued too much or some other variable could have been the cause of it. It is odd though that 2 of them were cracked, im thinking back in the summer when i had detonation/running leanproblems (due to bad MAF) it made the plugs too hot and cracked them... And now in the colder weather, the crack(s) have expanded and caused the misses.