iridium plugs, anyone using em?
Thread Starter
Le Mans Master
Joined: Feb 2001
Posts: 7,615
Likes: 142
From: Lake Simcoe..... Back in Black baby!!!
Toronto Events Coordinator
iridium plugs, anyone using em?
On the bike/atv forums I visit these plugs are all the rage. Tried one in my Rhino, and have seen a noticeable improvement in cold starts and more even throttle response.
On NGK's site, they also recommend them for auto applications, so, question is, has anyone tried them, and if so, what's your experience?
BTW, I have a stock L48 in a 73. Runs great, but due for a plug change, hence my curiosity...
On NGK's site, they also recommend them for auto applications, so, question is, has anyone tried them, and if so, what's your experience?
BTW, I have a stock L48 in a 73. Runs great, but due for a plug change, hence my curiosity...
Instructor
Joined: May 2007
Posts: 208
Likes: 0
From: Houma La
If you go to the NGK site and put in your info they will suggest plugs. I have a 78 L-48 stock 350 with duals and they did not suggest Those plugs. I have purchased the plugs but have not installed yet. The plugs they suggect are NGK v power #6630 UR4
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Any thing that costs more than the stock plugs are a waste of both time and money. In other word, save both money for gas and youself, those plugs are all hype and nothing else.
But their
will work as many will fall for it.....
But their
will work as many will fall for it.....
Burning Brakes
Joined: Feb 2006
Posts: 1,173
Likes: 5
From: Paducah Ky
I ran iridium plugs in race bikes. where high strung engines would foul regular plugs when idling in staging, etc. the iridium plugs would all but eliminate these fouling problems. I ran a set of these in my car and saw no advantage but if you have a fouling problem they may help. I don't know if there is a HP advantage or not. 2-3 HP is hard to notice when you have several hundred. 
Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
For a stock, unmodified engine, an oe type plug of whatever brand you like is all you need. Anything above that is simply money spent for no additional gain.
I tried the specialty, hyped plugs once...they got me once but not again. The ceramic insulators cracked on two within several months. I installed oe type and no more problems.
Years ago I worked for a chain auto center, we carried the house brand plug (made by Prestolite), and Champions. I found absolutely no difference in performance or quality between them...other than the Champions were a nice bright silver color and the house brand was a natural metal color, not polished.
Save your money and put the difference into gasoline to enjoy the car with.
I tried the specialty, hyped plugs once...they got me once but not again. The ceramic insulators cracked on two within several months. I installed oe type and no more problems.
Years ago I worked for a chain auto center, we carried the house brand plug (made by Prestolite), and Champions. I found absolutely no difference in performance or quality between them...other than the Champions were a nice bright silver color and the house brand was a natural metal color, not polished.
Save your money and put the difference into gasoline to enjoy the car with.
Drifting
Joined: Sep 2004
Posts: 1,625
Likes: 4
From: Miami FL
NGK's has them available for my 69 vette. I have been running them for the past 14K miles and no problems. I did find 2 plugs previously fouled really bad which were installed many owners before me. I am actually probably pulling the plugs tomorrow as I flooded the carb really good on Saturday not knowing it and while my car ran good after I finally got her started several hours later tonight she was sputtering under any type of acceleration. Idles smoothly but very rough sputtering on acceleration so I think I gassed them to death this past weekend.
Intermediate
Joined: Jun 2006
Posts: 41
Likes: 0
From: hooksett nh
Jacobs electronics says "if you spend more than $3 per plug you are wasting your money"
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Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
I had stock AC Delco plugs in mine...changed to NGK iridium plugs and noticed an improvement immediately. The main area I noticed, was in the upper RPM range (3000-4000). With the Delco's, the engine was "struggling" to maintain the RPM's 
(can't think of any other word to describe the situation)....when I installed the iridium's, I noticed (in the same RPM's) the engine was a lot smoother, more responsive and felt like it "wasn't struggling" to maintain the RPM;s...in fact it felt like it wanted to go faster....
The same carb, the same distributor, plug wires and even road location...the ONLY thing I changed were the plugs...
I have had absolutely NO problems from them and will continue to use them in the future!
(can't think of any other word to describe the situation)....when I installed the iridium's, I noticed (in the same RPM's) the engine was a lot smoother, more responsive and felt like it "wasn't struggling" to maintain the RPM;s...in fact it felt like it wanted to go faster.... The same carb, the same distributor, plug wires and even road location...the ONLY thing I changed were the plugs...
I have had absolutely NO problems from them and will continue to use them in the future!
Last edited by vetteguy75; Apr 15, 2008 at 08:13 AM.
Race Director
Joined: Sep 2001
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From: Wellington, FL
St. Jude Donor '11 thru '25
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
I think that one has to be careful when installing a new set of different plugs and then stating that their car runs much better. You really need to look at the condition of the plugs you took out before making a snap judgment. Just my 2 cents. 
Racer
Joined: Apr 2007
Posts: 361
Likes: 0
From: Sacramento (Citrus Heights) California
I work at a parts counter, and I've noticed that MANY people want Iridiums, but I generally tell them that they'd be much better off with a platinum or double platinum plug unless their engines spin up to the other side of 6000 RPM on a routine basis.
Personally, I'd run either OE Delco plugs, or the Bosch Platinum2+ (with the dual electrodes).
That's my $0.02.
Personally, I'd run either OE Delco plugs, or the Bosch Platinum2+ (with the dual electrodes).
That's my $0.02.
Pro
Joined: Oct 2007
Posts: 681
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From: Morris County, NJ
the irridium plugs are a benefit only if you plan on changing them after 100K miles of use. Many new cars come with the irridium plugs and can go up to 100K, but I change them at 50K anyway. Use the standard AC plugs
Pro
Joined: Nov 2004
Posts: 585
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From: Royal Oak MI
One of the horspower shows on Spike did a test this weekend with a new vs old plug and the new 383 I beleive, put out about 6 more hosepower with the new type plug.
I don't remember if it was the NGK but they had what looked like 4 points on them.
Is there any research that says new type plugs are a waste of money or is that just everyones old time thoughts?
I don't remember if it was the NGK but they had what looked like 4 points on them.
Is there any research that says new type plugs are a waste of money or is that just everyones old time thoughts?
Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
Spark plugs are just a part of an ignition system designed to work together, not simply a bunch of parts thrown together because of advertising hype or because of the color they are, etc.
We're talking about whether high grade high tech plugs like iridium will make a difference in a bone stock '73 L48, not a modified, built up high horsepower engine. That means points, condenser, smog control...the whole nine yards of early '70s small block emissions development that the owner already says runs great.
In a modern engine designed to go 100k miles without a tune-up iridium plugs are appropriate. In a '73, unmodified L48, all we're saying is that type of plug won't pass the cost/benefit analysis test.
I feel spark plugs other than oe type in that engine and expecting real benefits is like putting on racing stripes and saying they make the car go faster because they make it look faster.
We're talking about whether high grade high tech plugs like iridium will make a difference in a bone stock '73 L48, not a modified, built up high horsepower engine. That means points, condenser, smog control...the whole nine yards of early '70s small block emissions development that the owner already says runs great.
In a modern engine designed to go 100k miles without a tune-up iridium plugs are appropriate. In a '73, unmodified L48, all we're saying is that type of plug won't pass the cost/benefit analysis test.
I feel spark plugs other than oe type in that engine and expecting real benefits is like putting on racing stripes and saying they make the car go faster because they make it look faster.
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I thought these plugs came about because some brain surgeons in Japan decided to install engines sideways making changing a plugs (or anything else that used to take 10 minutes ) a 2 day ordeal, bottom line is, no performance gain, they just last longer and there is a longer time period between getting p'ed off at your honda
Last edited by MotorHead; Apr 15, 2008 at 06:43 PM.
Thread Starter
Le Mans Master
Joined: Feb 2001
Posts: 7,615
Likes: 142
From: Lake Simcoe..... Back in Black baby!!!
Toronto Events Coordinator
Spark plugs are just a part of an ignition system designed to work together, not simply a bunch of parts thrown together because of advertising hype or because of the color they are, etc.
We're talking about whether high grade high tech plugs like iridium will make a difference in a bone stock '73 L48, not a modified, built up high horsepower engine. That means points, condenser, smog control...the whole nine yards of early '70s small block emissions development that the owner already says runs great.
In a modern engine designed to go 100k miles without a tune-up iridium plugs are appropriate. In a '73, unmodified L48, all we're saying is that type of plug won't pass the cost/benefit analysis test.
I feel spark plugs other than oe type in that engine and expecting real benefits is like putting on racing stripes and saying they make the car go faster because they make it look faster.
We're talking about whether high grade high tech plugs like iridium will make a difference in a bone stock '73 L48, not a modified, built up high horsepower engine. That means points, condenser, smog control...the whole nine yards of early '70s small block emissions development that the owner already says runs great.
In a modern engine designed to go 100k miles without a tune-up iridium plugs are appropriate. In a '73, unmodified L48, all we're saying is that type of plug won't pass the cost/benefit analysis test.
I feel spark plugs other than oe type in that engine and expecting real benefits is like putting on racing stripes and saying they make the car go faster because they make it look faster.
Thanks to everyone else for your experiences too