Counterfeit spark plugs?

AutoZone in Victorville, CA

Screenshot 2025-02-23 at 8.34.48 AM.webp
 
NGK and Denso are even better :D
The 4.0 jeep engine with the waste spark system is very particular about it's plugs. Copper plugs only!

I don't know how it would react with Denso U -Groove plugs in it.

There are many threads on the jeep forums about installing fancy plugs and the engine simply will not start after.

The auto parts stores always push whatever special plugs are the plug of the month, I'm sure their guy gets a bonus for selling them but they are wrong for the jeep.

So I would rather just order plugs vs fight with the counter clown over a plug.
 
I don’t trust Amazon.

Only AAP for spark plugs.

I bought a set for a new to me BMW and about 6 months ago I bought a set for a Subaru 3.6 engine. Amazon was the seller not a 3rd party and both sets came sealed and signed as genuine. Visual inspection to the OEM NGK's looked alike w exception of the BMW logo. Installed the BMW plugs last week. So far so good. I'm sure Amazon had enough counterfeit claims they had to do something. Not that the seal and signature truly means anything.....
 
The 4.0 jeep engine with the waste spark system is very particular about it's plugs. Copper plugs only!

I don't know how it would react with Denso U -Groove plugs in it.

There are many threads on the jeep forums about installing fancy plugs and the engine simply will not start after.

The auto parts stores always push whatever special plugs are the plug of the month, I'm sure their guy gets a bonus for selling them but they are wrong for the jeep.

So I would rather just order plugs vs fight with the counter clown over a plug.

Looking at the plugs Rock Auto has for the 2002 Wrangler 4.0 I6, the Mopar looks like NGK, so if you went to the dealer, they'd give you NGK plugs in a Mopar box.

Denso and NGK both make good nickel/copper plugs.
 
Some RA warehouses are bad about tossing individual spark plug boxes in a much larger shipping box, often with heavy parts.

The people packaging have no idea why this might be a problem. Like the teenage bag boy who puts the bread on the bottom. The other day I had a teenager cashier put candy bars in a bag with raw meat. Same deal.
 
Spark plugs these days typically last 60K to 100K miles. The cost of genuine plugs spread over that mileage is pretty low. Why would you want to try to save money by buying on eBay? Get them from your dealer.
Buy copper plugs for a 20+ yr old jeep from the dealer? I doubt they still have them in stock.
 
I purchased Motorcraft replacement plugs for our 2.3L EcoBoost a few years ago from Rock Auto. Two of the plugs looked looked like they were dropped, the plastic shield that covers the threads was cracked and the center electrodes were deformed, though the boxes were not damaged. They replaced the plugs immediately and I was able to keep the damaged ones. I was able to correctly gap them and check the ohms and they were in spec. So I have 2 plugs for next plug change ;).
 
The AC Delco plugs I just got from Rockauto had no sleeves protecting the electrode from damage or gap changes from bouncing around. This on iridium plugs you aren't supposed to gap. Made me wonder if they were counterfeits.
 
07 Yukon Denali w/6.2L w/193k miles.
I bought a set of AC Delco #41-962 spark plugs from amazon.
I installed them gapped at .040".
After 22k miles started getting a P0300 code and the engine began to have a slight misfire at idle. It ran great otherwise. No CEL.
I pulled a plug and its gap was .065". I pulled the rest of the plugs and they were all .065". All the electrodes had worn badly in only 22k miles.
I concluded they were counterfeits.
 
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I seldom buy sparkplugs, but when I do, I buy NGK from Rock Auto, and after I get then I phone NGK and ask what to look at on them to tell if they are authentic or counterfeit. They know the differance and are helpful in telling what to look at to destinguish the differance.

So far, all I bought from them have been authentic.
 
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