Autolite replacement racing spark plugs are the plugs of choice for many professional racers. These plugs contain an Yttrium-enhanced alloy, which enables up to 8 percent reduction in side wire temperatures for improved durability and less preignition. Autolite racing spark plugs are available in colder heat ranges than most plug manufacturers to support modified engines. They feature a cut background electrode, which improves ignitibility, and faster flame kernel growth. Autolite racing spark plugs have a nickel plated finish for long life and corrosion resistance. Count on Autolite for the right plugs for racing performance!