If I took it in for warranty work would they bitch about the aftermarket plugs even though they are stock heat range?

 

you shouldnt have any problem. they cant tell you which plugs to run, they may try, but run what you want. I have them in my hawk, and its still under warranty.

 

Why would TR-55's be an issue?

My car had TR-5's platinum's when I bought the car new.

Some dealers as A$$'s and if they knew might try to make an issue if they thought they could push you around. Most will never know as they aren't going go check.

 

Hell no! The only possible way that the plugs could affect your warranty coverage would be if they directly contributed to some sort of problem. The onus at that point is on the dealer to prove that the plugs were the cause (theoretically anyway). Even so that wouldn't "void" your entire bumper-to-bumper warranty. Besides, as noted, the TR55 is a direct aftermarket replacement and GM can't force you to use a certain brand of plugs to retain warranty coverage - that's against the law. If your dealer hassles you about the brand of sparkplug you have, immediately go and find a new dealer <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />