spark plug issue..
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New Member
Joined: May 2001
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spark plug issue..
i went to my audi dealer today (commonwealth audi) to get my tune-up for 30K miles.
when i got the car back they had removed the denso iridium spark plugs and placed regular ngk plugs.
i went back to the service dept. and asked richard (the manager) why they had removed the plugs.
Here's what he told me:
"because those plugs don't work for your motor. the correct spark plugs have 3 prongs.
those densos don't therefore they might create misfires"
is he right? i'm not technically inclined to understand this stuff but what the hell is a prong?!
I do have the denso iridium model - IK20.
when i got the car back they had removed the denso iridium spark plugs and placed regular ngk plugs.
i went back to the service dept. and asked richard (the manager) why they had removed the plugs.
Here's what he told me:
"because those plugs don't work for your motor. the correct spark plugs have 3 prongs.
those densos don't therefore they might create misfires"
is he right? i'm not technically inclined to understand this stuff but what the hell is a prong?!
I do have the denso iridium model - IK20.
Junior Member
Joined: Jul 2000
Posts: 780
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The 1.8T plugs have one center electrode and 3 side (ground) electrodes.. (more)
However I always thought the theory was to provide more places for a spark to form (to prevent misfires), as opposed to providing a stronger spark.
A lot of people have been speaking highly of the Denso Iridiums, but I have heard the 1.8T is either hard on plugs or prone to carbon buildup. If that is true, then a new set of any kind of plugs will make an improvement. I have yet to see anyone compare a new set of factory plugs to a new set of Iridiums. I'm willing to bet they are identical in performance. I'd even be willing to bet the new factory plugs outperform the Iridiums since the ECU is "calibrated" for the factory plugs. It is for this reason that, unless you have made modifications to your car, it is rare that aftermarket plugs will perform better than the OEM plugs. 9 times out of 10 the aftermarket plugs are worse (ask any mechanic). I would like to try the Iridiums, but for the price I would like to see something that tells me they are noticeably better than a fresh set of factory plugs, and still outperforming them after 30K miles.
Paul
A lot of people have been speaking highly of the Denso Iridiums, but I have heard the 1.8T is either hard on plugs or prone to carbon buildup. If that is true, then a new set of any kind of plugs will make an improvement. I have yet to see anyone compare a new set of factory plugs to a new set of Iridiums. I'm willing to bet they are identical in performance. I'd even be willing to bet the new factory plugs outperform the Iridiums since the ECU is "calibrated" for the factory plugs. It is for this reason that, unless you have made modifications to your car, it is rare that aftermarket plugs will perform better than the OEM plugs. 9 times out of 10 the aftermarket plugs are worse (ask any mechanic). I would like to try the Iridiums, but for the price I would like to see something that tells me they are noticeably better than a fresh set of factory plugs, and still outperforming them after 30K miles.
Paul
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Re: The 1.8T plugs have one center electrode and 3 side (ground) electrodes.. (more)
I had those iridiums on my car on about 29K and they seem to be a lot smoother.
But now I'm thinking maybe it's just because they are brand new plugs.
They almost feel the same as they do w/ the new ones the dealer gave me.
In fact the difference in performance is so little that I probably wouldn't notice it if no one had told me that they had switched it.
I also did not see any difference as far as MPG. There might've been a 1 or 2 MPG difference.
Now i guess i won't be using these.
But now I'm thinking maybe it's just because they are brand new plugs.
They almost feel the same as they do w/ the new ones the dealer gave me.
In fact the difference in performance is so little that I probably wouldn't notice it if no one had told me that they had switched it.
I also did not see any difference as far as MPG. There might've been a 1 or 2 MPG difference.
Now i guess i won't be using these.
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mis-fires seldom happen in engines....
but wasted fuel because of poor cumbustion is a problem. You need 14.7 molecules of air for every molecule of fuel. Now, to make sure the fuel is burned adequately, give me electronic ignition, more spark and good fuel...
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Very true for OBD-II, or at least they're not supposed to.
It takes more electrical energy to make a bigger/hotter spark, not more metal. The spark only jumps from two points (a to b, not a to b+c+d), so it would seem that after the point the arc has formed the additional electrodes end up being, sort of "in the way."
This is over-simplified. Hopefully the idea comes across. The additional electrodes are still beneficial in providing more surfaces to form a spark, but once the spark is formed it does not go to all 3 electrodes at once. Only one at a time.
Paul
This is over-simplified. Hopefully the idea comes across. The additional electrodes are still beneficial in providing more surfaces to form a spark, but once the spark is formed it does not go to all 3 electrodes at once. Only one at a time.
Paul
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