Spark plug NGK or Denso

I use the NGK 1675 and have and factory black coils and haven't had an issue. I have had issues with with other brands.

NKGs are the exact same plug just different label and cheaper, and are much better than the stock plugs.

I like ac delco. But I recently used denso tt fine wire plugs I two different ls engines. What a difference in power. And gas mileage.

On NGK s website it says laser iridium (the oem ones) are good for 100k miles.

So far, the OP is on to something. I’m using these plugs and that are great. Next I’m going to try the NGK ZFR6T-11G Copper Nickel. These are OEM for later 2.5 motors. I have early 2.5. I’m curious how these slightly bottler plugs will run and especially since I run premium at all times. I’ll report back. But good find OP. These work great.

The 94553 Iridiums... the tip will last longer, but the gap will widen quicker as the ground electrode does not have a platinum disc on it like the Laser Platinums, so, the Laser Platinums will last longer.

The NGK iridium I mentioned before does not have the correct reach. The website says they are the same, but they are not. I think the database is wrong. When I go back to the copper NGK that does have the correct reach, the car drives better. I had all three in my hand and the iridium is shorter from the end of the threads down (reach). NGK websites say they are the same .75 reach. They are not the same in my hands. The copper plug is. NGK 4435.

Threw new plugs in it (NGK BKR7E; I like that 3 of my cars run these now... makes life simple)

This. I had the 7s in previously. I swapped to the 8s when someone mentioned they got better fuel mileage with them I didn't notice any difference.

The original dealership where I bought the van installed Denso spark plugs part # SXU22HCR11S which were supposed to have a gap of 0.044 but they all had either 0.039 or 0.040. Apparently no one checked the gap before putting them in.