NGK V-Power or Iridium?

[mcrn]

I want to do a tune up on a 2003 Yukon with the Flex fuel 5.3. It has 56K miles on it now. I bought it with 53K. I am trying to go through everything so I have a fresh start so I am aware that they are not required to be changed until the 100K mile mark. Plus just so everyone knows when they answer this I would probably never let a plug go 100K miles. So knowing this I see both the V-power and the Iridium is recommended for my engine. Should I go with the factory Iridiums or go with the V-power? And how long is the V-powers usually good for? I said I would not let them go 100K miles but I also do not want to be forced to change them every 30K either but I will if the V-power really does give better performance (even though I doubt they will). Thanks everyone! Also if the recommendation is for the Iridiums I will also probably go with AC Delco.

 

[xpeteyjtx]

Hey,
I would only go with the factory iridium spark plugs or the ones specifically listed in the manual... unless something has changed or GM made a mistake (unlikely). Looks like you need AC Delco 41-985

According the spark plug manufacturers, standard copper plugs can go about 30K, platinum plugs go 60-100K, and iridium about 120K. These are general values and will depend on what the car manufacture deems to be appropriate.

You can probably leave the stock plugs in there a little longer, I doubt you will see much difference.

 

[ZZman]

Out of those I would use the Iridium plugs. Otherwise I would go to the Laser Platinum.

I doubt you would see any performance difference. They would not last nearly as long as Platinum or the Iridium plugs.

 

[VWFox74]

I too would go with what the manufacture recommends especially if they are already using Iridiums. The engine was designed for those plugs and probably run best with them.

On my 1996 Dodge Grand Caravan I switched from the double platinums to Iridums because it takes several hours to change spark plugs on these vehicles. The rear plugs are mounted right against the firewall and I didn’t want to change them every again. So I used the Bosch +4 Iridium plugs, hoping to never touch the plugs again.

 

[mcrn]

Ok thanks guys thats the direction I was leaning. I have been doing some searching online and now I have found something interesting. The gap from the factory and the sticker under the hood says to gap them at .060 while the new ones come from the factory at .040 and all the new plugs say not to change the gap. GM did the change when they went from Platinum to Iridium and said to stay with the .040 gap with the iridiums. However when I am reading post from some people that went with the smaller gap they claim to have lost up to 2mpg and when they did regap them back to the .060 they got their MPG's back. Others of coarse say it runs great with the 0.40. So what do I do? Also the only plug that I have found that claims to be Iridium and comes from the factory with the .060 gap is Autolites.

 

[xpeteyjtx]

Well, you CAN gap the iridiums, but you have to be careful not to damage the electrode. I personally have never gapped an iridium, but I'm sure you can gap it without even touching the electrode (if you take your time).

Since you are worried about it, just try to open the gap a little bit, to around 0.05. Then install them like that. The gap is going to increase a teeny bit as time goes on anyway.

I would use the same make/model spark plug that came on your car. Or a different make/model that is listed in the manual

 

[sciphi]

Depends how much you want to change the plugs. I went with V-Powers in my 99 LeSabre that had 30k on the originals when I changed them earlier this year. There was a very noticeable increase in pickup. For the benefits and ease of changing on my car, I'm sticking with these.

But, not messing with those iridium plugs does sound nice.

 

[o2man98]

Laser platinums would be my choice as an OEM replacement. Iridium next in line. The V Powers are just a standard style plug.

 

[Titan]

Why not take out one of the original plugs and examine it. If it is in great shape, don't change them. I don't think it's a bad idea to remove each one and retorque it, that helps prevent a seized plug after 100,000 miles, but, this is a waste of resources. Yes, Virginia, plugs CAN last 100,000 miles without significant degradation in performance.

 

[mechtech2]

Iridium is my choice.
What are your present used gaps at?
This will tell you if the .060" is going to be OK. I favor .060", but maybe .050" -.055". .040" seems to tight .
And yes, you can set the gap, just be careful. Not the kind of
'be careful' that goes in one ear and out the other [like when your mother said "Be careful!" when you went to school in the morning, but use a fine touch and real care.

 

[HitManX]

I use coppers in my '01 Z71.

NGK seemed to pack the factory Delco units for a while too. FWIW

 

[ARB1977]

Had Iridiums in my Tacoma with 50K on them, replaced them the other day with stockers....much better feel. The Iridiums looked pretty worn but not bad.

 

[mechtech2]

You can get copper iridiums, copper steel, etc..
The copper is in the core to dissipate heat faster.
The tips are not copper. [well, OK... there are a few with copper cored electrodes as well].

 

[Mr Nice]

V-Power every 30K miles

 

[crw]

For what it's worth, on my 5.3L my stock wires were toast after about five years. They were actually causing a miss, and replacing them was a dramatic improvement.

 

[sprintman]

Iridium a no-brainer imo. Have them in Mazda and Outback but can't get then for BMW unfortunately.

 

[HitManX]

100k intervals on anything just is not smart. GM recommends this on ATF, plugs, coolant, etc.

Any improvement "felt" is simply going back to factory levels of performance.... I have yet to see anyone report the difference with data (dyno, 1/4 mile, etc) to warrant spending four times as much per plug. I have used copper core in five turbocharged vehicles and one nitrous without a hiccup.

 

[hhott71]

I had a 2001 5.3L Silverado that the previous owner put some cheap walmart champions in, They looked brand new but certainly had a random mis-fire.
I yanked those plugs and put in the correct GM specified plugs, The engine NEVER missed another beat.
They were in there 2 years later when I sold it to an INS co because of a texting teen girl (GRRR)

 

[Jason2007]

I would run the standard NGK platinum plugs.

 

[james49]

If you don't mind changing the plugs ever 30,000 miles, Denso iridium plugs with a .4mm center electrode are supposed to give better performance.