Don't Buy Bosch 4+ Plugs

I decided to try these when I replaced my plugs. DO NOT USE THEM. Trans Ams HATE these. I was getting shitty gas mileage, my acceleration went to hell, and actually lost horsepower with them.

 

When I took them out, they were all black and nasty after only a few weeks of driving. I had a custom tune as well.

Done