View Poll Results: Which Spark Plugs?
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Can we get a 'once-and-for-all' answer on spark plugs?
#1
10-04-2010, 08:37 PM
Join Date: Apr 2009
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Can we get a 'once-and-for-all' answer on spark plugs?
NGK, obviously... but Platinum or Iridium?
I hate to make this thread, and before you guys say it... yes, I did search.
In fact, that's the problem, I searched so much I found conflicting information and now I'm just confused.
So, I have >120,000 mi and just checked my service record and the plugs have never been changed. It scares me enough thinking about removing a plug from an aluminum head that's been there for 8 and a half years
but that's beside the point, which is that it's way past time to change them.
The trouble is, I don't know if I should go back with Platinum like the OEM ones, or go with Iridium.
From what I've been told, and read, IR is better, and I've heard newer Infinitis come with IR plugs stock (can someone confirm?)
I know lots of people run IR plugs with no problem, but I also read where Tim was talking about his tuner losing a couple VQs due to IR plugs
Anyway, here's the results of my searching, all in one place.
I hate to make this thread, and before you guys say it... yes, I did search.
In fact, that's the problem, I searched so much I found conflicting information and now I'm just confused.
So, I have >120,000 mi and just checked my service record and the plugs have never been changed. It scares me enough thinking about removing a plug from an aluminum head that's been there for 8 and a half years
but that's beside the point, which is that it's way past time to change them.The trouble is, I don't know if I should go back with Platinum like the OEM ones, or go with Iridium.
From what I've been told, and read, IR is better, and I've heard newer Infinitis come with IR plugs stock (can someone confirm?)
I know lots of people run IR plugs with no problem, but I also read where Tim was talking about his tuner losing a couple VQs due to IR plugs
Anyway, here's the results of my searching, all in one place.
Yes, the stock plugs are platinum. But I don't really think platinum is an appropriate material for spark plugs.
Although Pt is very corrosion resistant (which is a big plus), Pt is also a strong chemical catalyst (which is a big negative).
Pt is often used in aerospace combustion systems and jet engines to ensure combustion light off. Pt helps to prevent flame out when its used in the flame holders. Although this may be good for a jet engine, its not necessarily good for a reciprocating engine.
The reason why is because Pt is a chemical catalyst and its effectiveness as a catalyst varies with the type of gasoline you put in the gas tank.
The plug tips naturally get very hot while in use. If on the intake stroke a simple hydrocarbon fuel is used, the fuel/air mixture will only light off when the ECU gives the signal to light the mixture.
But with Pt, since it loves to catalyze ignition so easily, it may light off the mixture before the ECU gives the signal. This is called pre-ignition. And pre-ignition is never good. It can reduce power and sometimes even cause ping.
Because the chemical formulation of gasoline varies so greatly across the country, the catalytic activity of Pt relative to the gasoline varies accordingly.
If you live in an area where good grade gasoline (aromatic hydrocarbons) is always available its not much of a problem.
If you live in California where the gasoline is a nasty concoction of ethers, alcohols, olefins and aromatics, the Pt plugs will react differently. In fact, Pt is much more reactive with ethers and alcohols than regular aromatics. So in California, you are much more likely to experience pre-ignition than in Texas.
Pt introduces an unknown variable that can only cause problems.
Although Pt is very corrosion resistant (which is a big plus), Pt is also a strong chemical catalyst (which is a big negative).
Pt is often used in aerospace combustion systems and jet engines to ensure combustion light off. Pt helps to prevent flame out when its used in the flame holders. Although this may be good for a jet engine, its not necessarily good for a reciprocating engine.
The reason why is because Pt is a chemical catalyst and its effectiveness as a catalyst varies with the type of gasoline you put in the gas tank.
The plug tips naturally get very hot while in use. If on the intake stroke a simple hydrocarbon fuel is used, the fuel/air mixture will only light off when the ECU gives the signal to light the mixture.
But with Pt, since it loves to catalyze ignition so easily, it may light off the mixture before the ECU gives the signal. This is called pre-ignition. And pre-ignition is never good. It can reduce power and sometimes even cause ping.
Because the chemical formulation of gasoline varies so greatly across the country, the catalytic activity of Pt relative to the gasoline varies accordingly.
If you live in an area where good grade gasoline (aromatic hydrocarbons) is always available its not much of a problem.
If you live in California where the gasoline is a nasty concoction of ethers, alcohols, olefins and aromatics, the Pt plugs will react differently. In fact, Pt is much more reactive with ethers and alcohols than regular aromatics. So in California, you are much more likely to experience pre-ignition than in Texas.
Pt introduces an unknown variable that can only cause problems.
I was told by the tuners at Technosquare to stick w/the OEM platinum plugs BUT go one step colder, i've got a pretty modded NA. they said that the VQ didn't respond to the iridium plugs very well. i was really torn at first BUT the more & more research i do the more i realize it's the truth. Iridium plugs are good just not the BEST for OUR engines. most people who will tell you different are tryin' to sell 'em to ya.
Those are the stock plugs....NGK Platniums.
IMHO Iridium plugs aren't worth it. If you were running a power adder or nitrous or a high compression engine i'd say go for it...but for a stock motor with minor bolt ons, you are just spending more money for the hell of it.
IMHO Iridium plugs aren't worth it. If you were running a power adder or nitrous or a high compression engine i'd say go for it...but for a stock motor with minor bolt ons, you are just spending more money for the hell of it.
#3
10-05-2010, 12:22 AM
#4
10-05-2010, 04:47 AM
Be careful when picking iridium plugs. There are actually two kinds that are made by NGK. One type is good for 30k miles, whereas the other type is a 100k plug. Personally I have been using the one step cooler plugs in my 05 6mt (the NGK PLFR6A-11) and changing them out every 60k. I like changing them out regularly because it gives you an opportunity to check on how each cylinder is doing and see if you have that pesky spark plug tube seal leak. Might try iridiums next time though... we'll see
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#6
10-05-2010, 07:13 AM
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G35 sedan w/ too much money in mods
#7
10-05-2010, 08:28 AM
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#9
10-05-2010, 01:56 PM
#11
10-05-2010, 02:20 PM
Best performance plug? NGK coppers. Copper is a better conductor. The downside is you have to replace them every 30K miles. The upside is they're only $3.
Regardless of what you choose, you need to be very careful about removing those old plugs. The ideal way is to let the motor fully cool then turn all the plugs 1/8 turn and stop. Replace the coils and attempt to start the motor. This will blow out some of carbon resin that has formed around the plug base in the combustion chamber and reduce the chances of the resin cross-threading the heads as you try to remove the plug. Don't overly force the plug when removing it. If it starts to feel tight, go back clockwise and then counter clockwise, slowly working the plug out.
The plugs I'd go with are platinums unless you want to change out the plugs every 2 years or so. Iridums are basically marketing hype, though I've never heard of them failing. I'm sure it's happened, but I'd bet $20 the plug failures were on heavily modded NA or boosted VQs that were running excessively lean and leading to overly hot combustion chamber temps.
Regardless of what you choose, you need to be very careful about removing those old plugs. The ideal way is to let the motor fully cool then turn all the plugs 1/8 turn and stop. Replace the coils and attempt to start the motor. This will blow out some of carbon resin that has formed around the plug base in the combustion chamber and reduce the chances of the resin cross-threading the heads as you try to remove the plug. Don't overly force the plug when removing it. If it starts to feel tight, go back clockwise and then counter clockwise, slowly working the plug out.
The plugs I'd go with are platinums unless you want to change out the plugs every 2 years or so. Iridums are basically marketing hype, though I've never heard of them failing. I'm sure it's happened, but I'd bet $20 the plug failures were on heavily modded NA or boosted VQs that were running excessively lean and leading to overly hot combustion chamber temps.
#12
10-05-2010, 02:21 PM
Be careful when picking iridium plugs. There are actually two kinds that are made by NGK. One type is good for 30k miles, whereas the other type is a 100k plug. Personally I have been using the one step cooler plugs in my 05 6mt (the NGK PLFR6A-11) and changing them out every 60k. I like changing them out regularly because it gives you an opportunity to check on how each cylinder is doing and see if you have that pesky spark plug tube seal leak. Might try iridiums next time though... we'll see
noob i know .
whats the difference between the regular VS 1 step colder ??? ..
#14
10-05-2010, 05:03 PM
#15
10-05-2010, 06:59 PM
Join Date: Apr 2009
Location: Tallahassee, FL (or thereabout)
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Best performance plug? NGK coppers. Copper is a better conductor. The downside is you have to replace them every 30K miles. The upside is they're only $3.
Regardless of what you choose, you need to be very careful about removing those old plugs. The ideal way is to let the motor fully cool then turn all the plugs 1/8 turn and stop. Replace the coils and attempt to start the motor. This will blow out some of carbon resin that has formed around the plug base in the combustion chamber and reduce the chances of the resin cross-threading the heads as you try to remove the plug. Don't overly force the plug when removing it. If it starts to feel tight, go back clockwise and then counter clockwise, slowly working the plug out.
The plugs I'd go with are platinums unless you want to change out the plugs every 2 years or so. Iridums are basically marketing hype, though I've never heard of them failing. I'm sure it's happened, but I'd bet $20 the plug failures were on heavily modded NA or boosted VQs that were running excessively lean and leading to overly hot combustion chamber temps.
Regardless of what you choose, you need to be very careful about removing those old plugs. The ideal way is to let the motor fully cool then turn all the plugs 1/8 turn and stop. Replace the coils and attempt to start the motor. This will blow out some of carbon resin that has formed around the plug base in the combustion chamber and reduce the chances of the resin cross-threading the heads as you try to remove the plug. Don't overly force the plug when removing it. If it starts to feel tight, go back clockwise and then counter clockwise, slowly working the plug out.
The plugs I'd go with are platinums unless you want to change out the plugs every 2 years or so. Iridums are basically marketing hype, though I've never heard of them failing. I'm sure it's happened, but I'd bet $20 the plug failures were on heavily modded NA or boosted VQs that were running excessively lean and leading to overly hot combustion chamber temps.
Thanks for the tips on removal. Yeah, I'm nervous about the aluminum heads.
I knew about going back fwd and back out again if they got tight, but the 1/8 turn and then blowing out the resin is new to me, I'll give it a shot.