Spark plug Denso or AC DELCO

Believe it or not I got the Genuine AC Delco iridiums from Home Depot for $3 a plug.

Denso 3457 (FXE24HR11)

Why? It's the plug recommended in the owner's manual and I have never seen anyone have issues with this plug.

Why are they noticeably better than other equivalent plugs from reputable brands, I honestly don't know as it seems that the differences should be negligible. Plugs are one of the areas where the car is very fussy.

I finally changed out the OG Denso spark plugs on my wife's '10 RX350 at a shameful 415,000 kms. Wasn't idling rough but some low-rpms hesitation. Plugs still basically worked fine, though.

Toyota sounds like great deal if they actually use OEM plug (DENSO iridium). That part alone is \\~$18 each (you need 6).

DENSO , Iridium Long Life, SK20HPR-L11 Spark Plug

I would stick with the specd Denso, leave the coils alone.

Problem solved: I got a internally bad ac delco spark plug. Gap and everything was correct no cracks I could see literally just a bad plug.

So i just ordered a pack of 4s (the left one is from Denso Japan) from a local distributor carrying Denso spark plugs and of the 4, 3 are made in China and 1 is made in Japan. Comparing them side by side, the China ones definitely look subpar to the naked eye.

Problem solved: I got a internally bad ac delco spark plug. Gap and everything was correct no cracks I could see literally just a bad plug.

I highly recommend avoiding anything other than exactly what is specified in your owners manual, I currently have bad gas mileage because I was too curious to see if the desno two tip would do as good as the other stuff.