spark plugs, tr55 iridium or plane tr55 plugs?

**got-a-ls1** · 02-08-2006, 06:46 PM

bought some iridium plugs, tr55 ngk. Now i have seen a few posts that that say iridium isnt any good but they never really elaborated. I thought i read before they were the shit, but now im not so sure....

Are the iridiums gonna be any better then the regualr copper or did i just waste my money at 7 bucks a plug. I can still return them because i havnt installed them.

**Fastcar** · 02-08-2006, 07:51 PM

Originally Posted by got-a-ls1

bought some iridium plugs, tr55 ngk. Now i have seen a few posts that that say iridium isnt any good but they never really elaborated. I thought i read before they were the shit, but now im not so sure....

Are the iridiums gonna be any better then the regualr copper or did i just waste my money at 7 bucks a plug. I can still return them because i havnt installed them.

Iridiums supposedly are better if you use nitrous. I have them in my stock LS1 and I don't notice any difference, the car runs fine. I put them in because they're supposed to be the best plug on the market, the cost of the plugs is nothing compared to the dealer labor I had to pay to get them installed. I use Bosch Plus 4s Platinum in my other cars with no problems. I know that Iridiums have a very thin iridium center electrode, perhaps they're more fragile and prone to wear (just guessing). In any case, I'd suggest going with a good platinum plug instead of copper for longer life and better wear, 'cuz you don't want to be changing plugs frequently unless you're a masochist. The rear plugs are such a pain in the butt for us old farts to get out.

**SeVeReDiStOrTiOn** · 02-08-2006, 07:53 PM

I have the iridiums in and they are fine with no probs at all. They're "supposed" to have a higher melt down point and last longer...i've only had mine in for 4k miles but so far so good. Who said the plugs aren't any good? Someone might of said they're not worth the extra money...but I doubt they said the plugs aren't good.

**SeVeReDiStOrTiOn** · 02-08-2006, 07:54 PM

Originally Posted by Fastcar

I know that Iridiums have a very thin iridium center electrode, perhaps they're more fragile and prone to wear (just guessing).

Iridum is a very hard metal..that's why it can be so thin.

**got-a-ls1** · 02-08-2006, 09:20 PM

dunno who said it. Just read it in a post when i was searching. Something that the copper plugs would work better because copper is a better conductor or some shit. I figured the iridiums were a better plug, but didnt know if the others worked better in the LS1

ill keep the iridiums if they're gonna last longer. thnx for the replys guys....

if anyone else has any input lets hear it

**mbrownin** · 02-09-2006, 04:58 AM

Plug rank for durability:

1) iridium
2) platinum
3) copper

Plug rank for conductivity:

1) copper
2) iridium
3) platinum

**LS1LT1** · 02-09-2006, 06:13 AM

I like the basic NGK TR55 in my NA motors.

**SteveC** · 02-09-2006, 06:45 AM

I would go with the less expensive TR55, being that the plug base is steel going into an aluminum head, I like to change the plugs out every 2 years anyway.

SteveC

**Fastcar** · 02-09-2006, 06:06 PM

Also, be sure to put on a little moly anti-seize compund on the new plugs before you put them in!! The previous post just reminded me of that. It'll save you a lot of headaches the next time you change the plugs.