Spark plug NGK or OEM Subaru

So the BKR7EIXs are in and gapped to .028. Man what a difference. Everything is so much smoother and the engine doesn't feel strung out anymore.

Replace the spark plug with a genuine NGK plug.

I always get the oem brand because that works the best for your car. I get NKGs for my vw beetle

Iridium, tried and proven. Ruthenium looks like is an experiment by Ngk, I would give ti some time before these plugs prove themselves reliable before buying.

Another plug to give a try if you want to stay stock heat range - NGK's Ruthenium plugs LFER7BHX . Call it a placebo effect but after install cold start idle sure felt smoother and after 4000 miles they're running as good today as day one, gas mileage has been pretty good as well around 31 mpg +-1mpg @ 75mph. No cold start misfires. Overall a pretty solid plug for this engine and it's reasonably priced.

Brisks are throwaways that need regular attention by either regapping them every few thousand miles or replacing. You can run NGK 7437-9s for 20k in a stage 2 car without touching them. There's a big price difference so you get what you pay for.

Did my plugs 4 months ago with NGKand they still feel great.

I run NGK BKR6E's in my rabbit. I have had the best results and longest life from the NGK plugs. To the point that is all I run in any of my cars! LOVE them!

I've been pulling my CR8EIX iridium plugs out to check how they are burning a lot recently. I've been seeing some light ash deposits and high speed glazing and the iridium tips of the plugs are not as hot as I would expect them to be, i.e., they are not *white*.

I used the NGK plugs once and kept getting a pretty bad hiccup under hard acceleration.