NGK TR55 vs, NGK TR55GP

**VTXrider** · 03-05-2009, 07:41 AM

Sorry for my n00bness...

I am going to be changing my plugs and wires for no other reason than I feel like doing it. I have an '04 M6 with about 55,000 miles. I think it still has the original batery which I find amazing, I am not sure it's original but it is a Delco and it is on its way out. So when I am under there for the battery I figure I'll do plugs and wires also.

I bought the car about 7 months ago and do not have anything in the way of records so I am assuming that the plugs are also original.

So I have been reading alot and everyone mentions the NGK TR55s but I have not seen anything +/- on the TR55GPs. On the NGK wesite they list them as permium compared to the TR55s and call them a platnum plug, th eTR55s also have a platnum tip I think. So what is the difference, any opinion on which is better, the GP are only slightly more expensive but not a big difference.

Also after my reading I am going toward MSD 8.5mm wires, what length do I need. Is there any reason to get different wires?

**0rion** · 03-05-2009, 11:02 AM

I don't think you can go wrong with either plug IMO. Some people swear by the platinum and iridium (tr55ix) plugs so if you're one of those people then get them. I just run regular ole tr55's in mine and they've performed just fine for me. You'll be fine with either choice.
Your wires should already be cut to length. MSD's are a popular wire in the LSx crowd. I've ran them on my f-body for 10 years.

**Sarge** · 03-05-2009, 12:09 PM

TR55R....do it...do it now....like it when you do it....buy them from Mark at Kentucky Speed.....

**VTXrider** · 03-05-2009, 12:40 PM

Sarge, What is the TR55R, I don't see it on the NGK website when I search the GTO.

By the way I should say I am essetially stock, just CAI. My current plans is to keep it close to stock as far as the engine, just headers and a tune in the forseeable future..... If down the road I can afford a different car as the DD, who knows but then I could change all of this easily.

**VTXrider** · 03-05-2009, 12:48 PM

Also what gap should I use. I am reading, at least from T/A owners on the board, that the book reads .060 but there was a TSB for .043. What should I use?

**Sarge** · 03-05-2009, 01:12 PM

Sorry....I use the resistor type plugs....so I put a "R" on the end

I gap mine at .040
http://www.ls1.com/forums/showthread.php?t=83551
TR55's is what you want though.....

**VTXrider** · 03-05-2009, 01:28 PM

I notice in the link you say you use the TR55 because you "change your plugs every spring" if you were not planning on doing this would you still use those plugs? I am just wondering if the TR55GP will be more durable or not much difference?

I plan to not change the plugs for at least 25,000 but probably 50,000 miles.

**VTXrider** · 03-05-2009, 01:30 PM

make that 45,000 since I have 55,000 now and I am sure at 100,000 I am changing everything maintenance related.

**Sarge** · 03-05-2009, 01:57 PM

Originally Posted by VTXrider

I notice in the link you say you use the TR55 because you "change your plugs every spring" if you were not planning on doing this would you still use those plugs? I am just wondering if the TR55GP will be more durable or not much difference?

I plan to not change the plugs for at least 25,000 but probably 50,000 miles.

No they would be fine...every car is different.....I am all about maximizing the shit out of every part on the car and take everything to extremes on that car......

**VTXrider** · 03-05-2009, 02:01 PM

TR55s it is

Thanks Sarge.

**GTO1_OHIO** · 03-05-2009, 02:03 PM

I use the TR55IX. I normally change them each year but ran them an extra year last year to see if is saw any drop off and they were fine.

**0rion** · 03-05-2009, 02:56 PM

I've ran my tr55's for 3 years now....5500 miles.

**qwkgto** · 03-05-2009, 04:05 PM

I use the NGK tr6 but if I had a NA car id use the tr5 ,the autozone Nipindenso,is also a great choice,both have a two year free replacement,I replace mine ,some times two times a year.

**0rion** · 03-05-2009, 04:42 PM

Originally Posted by qwkgto

I use the NGK tr6 but if I had a NA car id use the tr5 ,the autozone Nipindenso,is also a great choice,both have a two year free replacement,I replace mine ,some times two times a year.

tr5's are gapped at .040" out of the box....the tr55's are gapped at .060" out of the box so if you're running the tr5's on a n/a motor you'll want to regap them. They're the same heat range though.

**qwkgto** · 03-05-2009, 04:55 PM

the ones i use have the v gap electrode,I gap em at 25 so the boost dont blow em out.

**0rion** · 03-05-2009, 05:01 PM

Originally Posted by qwkgto

the ones i use have the v gap electrode,I gap em at 25 so the boost dont blow em out.

both the 55's and the 5 have that v-gap. I think the only difference between the 2 is the gap. Running boost you should be running a tr6 though.....it's 1 range cooler than those 2. You don't have any problems with detonation?