Acdelco 41-110 OEM Gm 12621258 Professional Iridium Spark Plug - Set of 8

These are not Genuine OEM ACDelco spark plugs, made my truck misfire on all 8 cyls. Do not buy these. BEWARE.

When I opened the pack of 8 Plugs and each one was covered in grease and oil. The outside of the box looked perfect and was sealed. My guess is another customer Bought and switched out their old plugs and then returned the old plugs pretending they were new. I think a better job inspecting returns is needed to make sure this doesn't happen. I ended up buying a set local and paying 2 times the price because I already had my truck tore apart and could not wait on new plugs. They did refund my money without any issues so thats a plus.

Very well packaged and arrived as promised. Compared the new plug with the old plug that came out of the truck. It has identical identification numbers. OEM product for 2010 Chevy Silverado 1500

I purchased these spark plugs in December 2018. For period of 3+ months, they made a significant difference in my vehicle. Gradually, we started noticing sluggishness and even pinging. We changed to a higher octane gas and continued experiencing pinging. Yesterday, we decided to remove the plugs as we feared fouling. We then discovered that the 'new' plugs with less than 7K miles were INCREDIBLY worn. The 'Iridum' center electrode protrusion was rounded up to nearly the ceramic insulator base. Wear was about the same for all plugs. My vehicle performs very well with AC Delco products and unless their quality control or materials used to manufacture them are now substandard, these are not definitely AC Delco.

All plugs came individually boxed, gapped right, and this is not a knock off real deal ac delco

I had bosch platinum wich are no good for my truck it gave me a ramdom misfire code, so I'd changed them to these ac delco iridium and i had to gap them to .060 according to the specs for my truck 2002 Chevrolet suburban 1500 LT 2wd with a 5.3L vortec, and they worked perfectly fine, they took the code away and paid half the price of what they wanted at the autostore, definitely recommended

Garbage. Truck developed a miss shortly after installing these plugs. New wires were installed at time plugs were changed too. Put new coil packs on. Still a misfire. Finally pulled a plug to find this JUNK! 7 of the 8 the electrode is completely gone. Did not gap as I've been told you can chip iridium plating off. They all measured very close to the recommended .040 anyhow. These plugs have less than 4000 miles on them. No response from the seller thus far.

Exact replacement for the factory plugs on my 2010 Silverado with 5.3 even through Amazon says it isn't. Best price I saw anywhere else and on top of that, GM has rebates on AC Delco spark plugs right now. After rebates, it's only gonna cost me $80 to install iridium plugs and upgraded Delco wires on 2 trucks.