Spark plug NGK or Denso

i just switched over to some ngk 91006 last week which smoothed out the idle. haven’t put enough mileage on them to give a solid review but it’s what many recommend and the car felt great at the track this weekend so i’d say they are definitely a solid option.

After further review i returned the autolite plugs and got NGK LKAR7BIX-11S Iridium IX Spark Plug (93501 Iridium Ix). ????

I also paid roughly $50 for a set of 4 iridium NGK spark plugs for my Audi a few years ago....even with an extra cylinder or two it shouldn't cost even half as much as they are estimating here.

On Rock Auto Denso...Denso double platinum spark plugs for $4.32 each, but I would opt for the NGK Rutheniums for $8.32 each because they last longer and provide better combustion in these older engines

I went with the NGK rutheniums as they're also rated for 100k and were slightly cheaper on Rock Auto than the iridiums. Supposedly they maintain fuel efficiency longer over their life than iridiums

Densos. Buy them off rock auto.

The Denso IHKs are my go to for the last 10k on their tune.

Either one, but I found the Denso to be cheaper and easier to get. No issues with them.

Yesterday my new Ariens made its maiden voyage up here in Maine and began misfiring under load. Called the dealer where I bought it and they said it may be the spark plug. Ariens apparently puts cheap Chinese plugs (Torch brand) in their machines. Long story short, new NGK and all is well. Powers through them berms like a pro.

after putting the new ones i changed all the spark plugs too, to fit them properly with new wires. but the car runned roughly, so bad..and when mechanic unscrew the new spark plugs to see, they were carbonized black, with just a ride around.