Spark plug NGK or Autolite

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.

These are Autolite plugs, not Motorcraft. Which means the plugs in this vehicle have been changed before, that probably has a little to do with why it was easier than usual to get these out. By the looks of the plugs and the lack of carbon buildup and corrosion (the two factors that cause these plugs to size the most) I'd say they weren't in there for a very long time either. Going by my experience with Autolite plugs in Fords (very little experience as I work on Euros mostly) if they don't start misfiring right away it's usually within a couple of months.

Throw them away, they're shit plugs. Autolite just didn't crack the code for making quality iridium plugs at a super cheap price. I wouldn't even put these in my lawn mower.

Don't buy Autolite spark plugs. They suck. I had 2 out of 4 in a pack that were faulty and failed within days of installing them.