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Spark plugs


diRtY

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Hi i just wanted to ask you what kind of spark plugs are better for my 94 sts

i have some friends in vwvortex and in club 1.8t and they say that copper are better because they are cooler, but now i have on my car ngk iridium...

which ones are better copper, silver, platinum or iridium???

thanx

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OE AC-Delco dual platinum. It's what your car came with and it's what it should use. The notion that copper plugs are "cooler" is hogwash. "Cheaper", yes, but "cooler", no.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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they say that the spark is cold and that the combustion cam stays colder and colder is better... and that iridium spark is hot so the cam is always hot...

I'm not sure what they're talking about. "Combustion cam"? Do they mean "intake cam"? Regardless, the construction of the plug has nothing to do with the temperature of the camshafts, if that's what they really mean. Your car was designed and validated with dual platinum plugs, and will run as intended on dual platinum plugs.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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The Iridium plugs are very good plugs if they are the correct heat range. I believe they are being used in the newest Cadillacs.

The Northstar was designed to run optimally with dual platinum plugs. AC was the original brand, I find that Champion also works just fine.

"Combustion cam" makes no sense to me. I think someone is confused on engine terms.

Regarding the heat range of the spark, you need to use the correct heat range for your engine for it to work correctly. A cool plug will be useful in a race engine to reduce the likelihood of pre-ignition.

Using a cool of a plug in a daily driver is not good. It will tend to build deposits while driving at normal street speeds, and then when you start doing quick accelerations the deposits usually get melted onto the ceramic insulator. These melted on deposits will, after a time, start shorting or bridging the spark plug gap. Using the correct heat range is usually the best choice for a street driven car. The cooler plugs were designed for cars that are being driven as race only or the plugs are changed depending on if you are racing or street driving.

Your car takes AC/Delco 41-950 spark plugs (these are dual platinum), I would recommend using them for the best results.

-George

Drive'em like you own 'em. - ....................04 DTS............................

DTS_Signature.jpg

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If you feel the need to change them (they probably don't need changed) use AC Delco. I bought the bosch plugs and the car ran poorly. Put in a new set of AC's and it ran fine. No better than the originals with 95,000 miles though. Unless one is broken i think you are throwing money away.

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If you feel the need to change them (they probably don't need changed) use AC Delco. I bought the bosch plugs and the car ran poorly. Put in a new set of AC's and it ran fine. No better than the originals with 95,000 miles though. Unless one is broken i think you are throwing money away.

I agree with you on the Bosch plugs. I am not sure which ones you used , but I used the Bosch Platinum Quad Tip. While the engine seemed to work OK, there was a feeling of power loss and the exhaust smelled a little rich.

After a couple of months I put back my "old" Champions and the solid power returned and the exhaust was cleaner.

No big difference in mileage either way though.

In my opinon "Toss the Bosch".

-George

Drive'em like you own 'em. - ....................04 DTS............................

DTS_Signature.jpg

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When it comes to an item like spark plugs I think the original set that the engine was designed and tested with is probably best for the following reasons:

1. This is a relatively inexpensive part that will last a long, long time in newer cars. Therefore cost of manufacture or re-sale is not the most important factor. Stated another way, if there was any HP available from simply a sparkplug change, GM or any other make would change their design or simply install another's patented design and pay 'em. This would be very cheap incremental horsepower and maybe very little compromise (see below).

3. There is some horsepower "left on the table" in a Caddy or almost any other consumer vehicle. However, large improvements involve large costs or compromises - there is no free lunch.

For example: Even on this relatively conservative site - It has been agreed that installing a free'er exhaust system and mufflers will make more power. However, even the owners who have installed the equipment and are very happy with the power - admit that the car it is noiser. They might like the noise and all, but there is a power/noise compromise regardless.

I probably feel the same way about lights, oil, filters and a plentiful plethora of other such mechanical minutia. Let the Engineers get paid to worry about that stuff. If they really screw up, they are judged in the market place - once.

Since Caddy is at the top of the GM heap, it probably receives the finest engineering, (including long-term validation) and has most everything "wrung out" while maintaining compromises that its market desires.

my 3-cents B)

Add power to leave problems behind. Most braking is just - poor planning.
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Thanx for all your comments and sorry about my english...

it was just a question i have now iridium spark plugs but they told to that i should ask the experts...

i feel that the plugs are working fine and mmmmhhhh here in mexico i won´t buy any ac delco cause it´s not oe it´s made here and it´s not like the one you have in the states

my dad owes a 82 fleetwood coupe de ville with the 4.1 tbi engine and he never buys any parts here cause:

1. that car was never sold in mexico

2. if you get any parts for that car you pay a stupid amount cause you know here in mexico they thin it´s a caddy you are rich

3. they don´t even know that car

4. we´ve got relatives in califprnia so if we need any part we just call them

thank you all for your help

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I'm sure the iridium spark plugs are better than the platnimus because the electrodes can be smaller and thus make a bigger spark.. So sure they might perform a teeny bit better but I'm not sure if they will last as long.. Never tried or tested.. If you use regular plugs in the NS* engine it's fine but you have to change them often. The 2000(i believe) and later models have a different coil setup so it might not even make any difference at all there (coil on plug i think it is)

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