J_God

Heres what i am having trouble with.. I have a 99 ss and i work at auto-zone after looking into the tr55's (i keep reading that i should be using those plugs for a tune up) but they are copper plugs, the other part number i recieved for the tr55 lx plugs were an iridium plug... And the car from the factory takes platinum plugs so im unsure on what to do.

thunderstruck507

iTrader: (18)

you can use either...most use the copper plugs because they are cheap and aside from lasting longer there isn't really much point in the high dollar plugs but people tend to change them ahead of schedule anyway

demonspeed

iTrader: (7)

GM changed their factory plugs/replacement recommendations in the mid-2000's to iridiums. The ACDelco number is 41-110. I personally run the AC's, but TR55IX would be fine.

The main thing to consider with a copper like TR55 is you'll need to change them more often. So, while you might save money on a copper plug over an iridium, you'll end up spending that amount multiple times rather than theoretically only once with the iridium (which are pre-gapped, 100k mile plugs).

J_God

But i was under the impression changing the plugs to a different material such as copper rather than platinum(what it calls for) could cause the car to run bad and could be detrimental to my engine.. And obv i do not want to do any harm to my engine

thunderstruck507

iTrader: (18)

either plug is designed to run at the same heat range, I am confident you would find a majority of the users here are running the copper plugs with no ill effects (aside from having to change plugs more frequently as noted above)

I noticed not difference in how my car ran on the street or track when switching from the factory plugs to NGK TR55s

99z28monster

iTrader: (3)

No ill effect from those plugs. Go for it and join the masses we have free cake and ice cream!!

demonspeed

iTrader: (7)

Come on over and have a drink