Most spark plugs now come pre-gapped from the manufacturer, however, this was not the case in the past. While inserting spark plugs, it is suggested to double-check that the gap is set according to the vehicle's specified setting. Despite the fact that many spark plug manufacturers advertise that their plugs are pre-gapped, this does not always imply that the plugs are properly gapped for a particular vehicle. Some spark plugs are already spaced out for certain automobiles, so checking the box can save the customer time.