Review on Autolite AR3932 4PK Performance Racing Non Resistor by Ivan Carson

I bought spark plugs for my car with nitrous oxide. Viewing under magnification we noticed very small shiny spots on the ceramic (similar to piston burnout aluminum but smaller) which was a cause for concern. However, we compared them to new, unused spark plugs and found that they also had small spots. After cutting the fork, I found that the stains go through the entire ceramic part of the fork. Not a problem once you realize that these aren't aluminum pistons due to poor tuning, but part of a ceramic formula. Otherwise an excellent product.