Spark plugs have evolved. New technologies like platinum, iridium and electrode designs have changed how technician service of the ignition system.
With some spark plugs gapping the plug is an essential first step. For other plugs, gapping the plug is not required or using old school methods could damage the plug and cause misfires. Andrew Markel discusses what spark plugs need to be gapped and the tools required to get the job done. This video is sponsored by Autolite.