This is my first post to this forum, and there will probably be many more to come.

I've heard that the NGK TR55's are the way to go on our cars other than the stock 91-906 Delco plugs. I was wondering if there is that big of a difference between the regular V-Power plugs and the Iridium or Platinum plugs? Is there an reason I should fork out the extra cash for the Iridium or Platinum plugs?

Don't have many mods right now, so I shouldn't need a colder plug.

I was replacing the oil pan and timing cover gaskets/seals under my car and decided to check the plugs. I took out a 91-906 Delco plug that I had installed not too long ago (about 13,000 miles ago) and low and behold, the platinum puck was missing on the electrode. It increased the gap on the plug by about .015". So I am going to replace the plugs with the NGK's. Just need to figure out which ones I want to get...

Thanks a lot.

 

No real need to go colder unless your going to go with a power adder soon (supercharger or nitrous).

When I had the bottle, I ran NGK TR6's. I took it off and I'm running ACDelco plats, and they're awesome.

 

go with the delco plats. worth the $ IMO! I Love Mine!!!

 

Well, I guess that's what I was saying in the previous post... The AC Delco Platinum plugs are 91-906 plugs. I've only put 13,000 miles on them, and already the platinum pucks are coming off of them. So I would rather go to the NGK. People have said they've had problems with the pucks coming off of the AC Delco platinums, and said that the NGK's are great. Just wondering if I would be better with the regular NGK's or the Iridiums or the Platinum NGK's.

 

I use the NGK TR55`s and I change them every 15,000 miles.They are cheap and they work great.

 

How do those plugs (TR55) look when you take them out after 15,000 miles? Still in good shape and have a good gap?

 

I have had AC's twice.At three thousand miles the pucs are gone.That leaves a standard plug.It's a hot plug for emissions,and (supposed longivity))and they get kind of mushy on my car..NGK's are a colder running plug,and really perform well.Weather you decide on a plat or not is up to how often you like to change plugs.I change mine about every 5000 mi or so.My02(non Plats).($1.79 at Napa).NGK

 

The AC platinums are supposed to last 100k, but we know better. I replaced mine at 100K, and most of the pucks were gone. At 160k, I replaced them again, and three of the pucks were gone. Plus, one of the plugs was stuck in the head, and I nearly detroyed the threads removing it. If I were to do it over again, I would buy platinums that dont have the puck design, and change every 60k, or go with copper, and replace every 30K.

Actually, when I do it again, I wont buy a car that's a hassle to change the plugs.

 

Here's cross reference of the different plugs along with the part numbers: Stock heat range:

AC Delco 41-906 (platinum, stock plug)
AC Delco Rapidfire 3
AC Delco R44LTS
Accel 516
Autolite 106
Bosch HR9DPX
Champion RS14YC
Motorcraft AGRF42
Nippondenso T16EPR-U
NGK TR5 (.035 gap)
NGK TR55 (.050 gap)
NGK TR55VX (platinum version of the above

 

I've heard that some people use the Delco Rapidfires... How are those plugs? Any comments on those? How are they different than a conventional copper plug?

 

I seriously doubt your going to see much difference from an Autolite $0.99 plug and an Iridium $9 plug...personally I have always been very happy with Bosch Platinum plugs, theres no puck to come off, the entire center electrode is platinum. Top that off with the fact that they are short plugs so clearance is better, and they are less than $2 each, its killer

I've also used NGK TR55's with no problems.

 

I like both the ngk's and the regular ac delcos R44LTS, i'd use the ngks but the plug wire terminal tends to unscrew. If you like the delcos but dont want to use the platinums the R44LTS is a good choice, it's a real short plug and there cheap.