: Iradium spark plugs for 99deville? Better or worse? What the best plug & wires??



RENO99DEVILLE
12-28-07, 09:30 PM
Iradium spark plugs for 99deville? Better or worse? What the best plug & wires for saving gas??:stirpot:??

Submariner409
12-28-07, 09:38 PM
No plug wires in a '99 ? DON'T switch to Iridium plugs. ACDelco 41-950 or 41-987 double platinum plugs, $5.05 ea. from www.rockauto.com (http://www.rockauto.com). Nothing else. Don't worry about plugs until 100k miles. Seriously...... If you get anal, do the plugs and boots together, and make sure the coil cassettes are clean and seated correctly. Learn to recognize snake oil and bum dope. You'll save big bucks.

Look at your companion post about gas mileage..............

AJxtcman
12-28-07, 09:49 PM
Well GM has been using AC DENSO plug in some applications. They are Iridium in all or most applications.
Now in 400000000BC a space craft crashed into the earth and created the gulf of Mexico.

Oh wait that was a different thread awhile back.

OK it was a meteor and Iridium is not Natural, because it is not from earth correct?

I have you all lost by now I hope.:stirpot:

Do some research please on Iridium. :eek:

Iridium plugs are #1 says GM:stirpot:

Ranger
12-28-07, 10:14 PM
The '99 still had plug wires. 2000+ is COP ignition. Switching plug wires won't improve mileage.

Submariner409
12-28-07, 10:27 PM
AJ, Does GM now recommend Iridium electrode plugs for pre-'06 N* engines ??? Is there a new TSB on this ??? If so, what is the new recommended plug change interval....still 100k ??? What are the new p/n's ???

Those damn '99 wires will get me yet........

AJxtcman
12-28-07, 10:51 PM
:hmm::hmm:I did not intend that towards you.
I have rad about the Iridium plug after seeing AC DENSO. I tried a search on AC denso and came up with nothing:mad:


I don't know

I have several sets of new plug from new engine I have installed.

I am a nice guy and install the old plug in the new engine. :histeric:

Well they only have 20k or so on them. That is like 1/5th the life:histeric:

yeah I love customers:hmm:

Zorb750
12-29-07, 05:53 AM
Irridium may be a waste of money for you. The thinner electrode should make a better formed spark, with higher tolerance for a wider temperature range, but it's not quite apparent how much better it will actually run the car. Densos with double platinum electrodes seem to have a better design and resist buildup better than ACDelco platinum, so that would be my suggestion. Either way, spark plug wires won't help your mileage unless any of the old ones are either dead (high resistance or open circuit) or have leaking insulation (lightning under hood in the dark).

I like NGK platinum plugs too, but only had them for about 30000 miles, prior to engine swap for head gasket reasons (quicker to swap and have original engine repaired and timeserted and sell it than wait to repair the original with no car.) They were still perfect when the engine was taken apart though.

Cadillacboy
12-29-07, 10:31 AM
Ac Delco is the best one ,so far so good for me yet for everyone I think

AJxtcman
12-29-07, 11:24 AM
I need to find some AC-DENSO plug #s
I thought they were Iridium

Submariner409
12-29-07, 12:13 PM
AJ, if you look at the new run of ACDelco platinum plugs which superceded the Denso line, you'll see that they, too, are made in Japan. Any guesses as to who's making offshore ACDelco platinum plugs?

There appears to be no AC-to-Denso cross reference for Cadillac N* plugs in either the Accel or Motorcraft online documents. Lots of plugs, but AC 41-950 and 41-987 draw a blank. (Motorcraft is APP104)

AJxtcman
12-29-07, 03:13 PM
AJ, if you look at the new run of ACDelco platinum plugs which superceded the Denso line, you'll see that they, too, are made in Japan. Any guesses as to who's making offshore ACDelco platinum plugs?

There appears to be no AC-to-Denso cross reference for Cadillac N* plugs in either the Accel or Motorcraft online documents. Lots of plugs, but AC 41-950 and 41-987 draw a blank. (Motorcraft is APP104)

The boxes and the plugs say AC-Denso

AJxtcman
12-29-07, 04:15 PM
I have 3 ACDelco plug at home with me. 1 also has NGK printed on it. It is from an Escalade.

All 3 have different electrodes and they are all Platinums. I will do some more research on the Laser cut Electrodes.

This is a little info from ACDelco

ACDelco Professional Iridium Spark Plugs
ACDelco Iridium Spark Plugs are the latest evolution in high-performance plugs. The natural properties of iridium, with a melting point approximately 700 degrees Celsius higher than platinum, helps enable the plug to burn fuel more efficiently and to deliver better performance. As a result, the iridium plugs have a minimum service life of 100,000 miles.*

Since iridium is one of the densest materials found on earth, the iridium-tipped center electrode is 50 percent the size of a platinum electrode and 20 percent the size of a conventional nickel electrode.

The secondary microdischarge of the center electrode burns off carbon deposits as they form for superior antifouling performance that, along with the tapered cut-ground electrode, offers enhanced flame spread during combustion.

The specially designed electrodes increase the electric field strength at the gap, reducing the voltage required for sparking to begin, for improved cold starting and quicker acceleration.

The application coverage of ACDelco Iridium Spark Plugs continues to grow, with the plugs backed by a 100,000-mile limited warranty.

*Service life varies with individual driving conditions.
http://www.acdelco.com/i/parts/spark-plugs/sidebar/pic_iridium.jpg


ACDelco Professional Platinum Spark Plugs
ACDelco Professional Platinum Spark Plugs are perfect for engines that run on conventional plugs and newer engines that require platinum plugs. ACDelco Professional Platinum Spark Plugs can provide up to 100,000 miles of service before requiring replacement.*

Professional Platinum spark plugs also feature:


Dual platinum tip for improved resistance to spark erosion, fouling, and corrosive combustion chamber environment
A ribless insulator that improves the plug-to-boot seal
A platinum center electrode and a platinum pad lower the ignition demand voltage and reduce possible flame kernal quenching
One-piece integral suppressor seal helps reduce radio frequency interference, meters spark plug energy to help provide long electrode life, and seals against compression leakage
Maximum engine performance over time
A corrision-resistent shell to keep up with the demands of any vehicle
Spark gap remains virtually unchanged during the life of the plug
Meet increased auto industry performance and reliability requirements
Available for most makes and models
100,000-mile (160,000-kilometer) limited warranty

*Service life varies with individual driving conditions.
http://www.acdelco.com/i/parts/spark-plugs/sidebar/pic_platinum.jpg

Submariner409
12-29-07, 07:06 PM
Please take a long, hard look at the 2 pics of spark plugs in the above post.

Both examples are AC Double Platinum Professional units.

This is a new ACDelco 41-985 Iridium tipped unit. See the difference? Click on the pic and scroll in.

Around $7+ each in a few suppliers' sites.

AJxtcman
12-29-07, 07:45 PM
Please take a long, hard look at the 2 pics of spark plugs in the above post.

Both examples are AC Double Platinum Professional units.

This is a new ACDelco 41-985 Iridium tipped unit. See the difference? Click on the pic and scroll in.

Around $7+ each in a few suppliers' sites.

I am confused even more.
I know I got a set 0f AC-Denso plugs. I was so surprised that they were not AC-Delco I did some research that day. They were IRIDIUM.

This is from an AC-Delco website http://www.acdelco.com/parts/sparkplugs/identification.jsp

http://i224.photobucket.com/albums/dd25/AJxtcman/1-2.jpg
http://i224.photobucket.com/albums/dd25/AJxtcman/2-1.jpg

AJxtcman
12-29-07, 08:39 PM
NGK #PZTR5A 15----AC-Delco #12567759
http://i224.photobucket.com/albums/dd25/AJxtcman/forum/plugs/NGK2.jpg
http://i224.photobucket.com/albums/dd25/AJxtcman/forum/plugs/NGK.jpg

New AC-Delco Plug #41-932
http://i224.photobucket.com/albums/dd25/AJxtcman/forum/plugs/new.jpg

Pointy Electrode AC-Delco short #41-985 Long #12571164
http://i224.photobucket.com/albums/dd25/AJxtcman/forum/plugs/pointy.jpg
http://i224.photobucket.com/albums/dd25/AJxtcman/forum/plugs/pointy2.jpg

All Three
http://i224.photobucket.com/albums/dd25/AJxtcman/forum/plugs/3.jpg

They are all listed as Double tip Platinum

Submariner409
12-29-07, 10:40 PM
:rolleyes:AJ, Just for grins and kicks, Google "acdelco 12571164".

AJxtcman
12-30-07, 02:10 PM
38489

Submariner409
12-30-07, 02:32 PM
Yep, 41-985, Iridium, and not recommended in the ^^ (Dec. 2003 !) TSB for the 4.6L Seville/deVille series.

Look at post #2. Your TSB answers the question.

AJxtcman
12-30-07, 04:06 PM
I am still confused on the AC-denso