Question on AC Delco plugs

[swathdiver]

No iridium shows up there for my truck

OK, for whatever reason they do not recommend them for yours. I wonder why? I know this has been discussed before but the internal search is not working right, you have to use an external search engine to find out why and if you can run them anyways. I think you can.

 

[Fless]

Here's a repost from 3 years ago (https://www.tahoeyukonforum.com/threads/spark-plugs-platinum-or-iridium.93939/#post-1120759)


My '04 5.3 also came with 41-985s. I inquired directly to ACDelco about the unavailability of those, and this is the response I received:

Regarding your inquiry for spark plug for VIN [cut], we show the correct part number to be 41-962. The 41-985 are discontinued and they do show to supersede to 12621258 which is not available and they are no longer recommended for your vehicle. The engineers have made the change to the new spark plug.

If you have any other questions, please feel free to contact our experts at the ACDelco support center by dialing 1-800-ACDELCO (223-3526).

We appreciate your business.

Regards,

ACDelco Internet Response Team

 

[Rayyy]

Me too... The AC Delco search site also does not does not show any Iridium plugs.

 

[Rayyy]

Read up on a few other forums about the bulletin to change spark plugs:

ACDelco announces that 2006 and older, as well as some 2007, spark plug service applications
covered by the iridium spark plug 41-110 have moved to the platinum plug 41-962. For the
older model years, GM used a double platinum spark plug in production, and these older
applications are to be serviced with the double platinum plug 41-962. 2007 and newer
applications used iridium plugs in production and service requirements will remain assigned to
the iridium plug 41-110. Both plugs meet original equipment specifications for the applications
designated. Catalog changes for the Epicor and WHI systems will be updated in the June
release 2013. ACDelco recommends you begin adjusting your stocking requirements for the
41-962 in preparation of the upcoming catalog updates.

In cases like this, I always wonder whether the “engineers” are telling the truth or whether it is one of GM’a marketing ploys for whatever plan they are concocting.

I did also however read up on some people saying that they’ve actually gained acceleration and MPG by switching to the platinum plugs.

Perhaps platinum plugs with the now shorter .040 gap (vs the original .060) are superior to Iridium in the 5.3 Vortec??

 

[Rayyy]

I pondered whether the switch back to platinum for pre-07 trucks was a way to remain competitive price-wise on maintenance of the older trucks, but that however doesn’t make much sense since:

41-110 is $8.99
41-962 is $7.49 (only .50 cents less)

And if Iridium is no longer approved for use with the 5.3 Vortec... Why is the NGK TR5IX (7397) Iridium plug on the O’Reilly fit list???

 

[Rayyy]

Here is an interesting summary of the “best” plugs for the 5.3 Vortec:

https://sparkplugsguru.com/best-spark-plugs-for-5-3-vortec/

Although it lists 41-110 at #1, the second on the list is the NGK TR5IX, in bold letters states that it will prevent misfire.

While the third is the 41-962 Platinum, highlighting in bold that it will increase MPG.

Gimmicks? The saga continues.

 

[Rayyy]

Fei... I ended up picking up some 41-110 plugs. Somehow I couldn’t justify going back to platinum.