Andy and Group, Just to let you know, There are two types of Platinum plugs. The standard plug, copper and the platinum plug like the copper with the single bent over post for the fire. Then there is the Platinum + 4. These are the least line of resistance in a plug. I have run them for over 5000 miles with no problems, you can see what Bosch say's about them along with other manufactures in trade magazines and on the web site. I believe what Rob was talking about was the standard tip platinum, which I don't sell or use not the + 4. There is a difference and the + 4 does makes a difference in the idling and firing. Just a note. Yes andy, Tune up's do go right. If you ask 10 people their opinion you will normally get 8 different opinions. John hervey http://www.specialtauto.com/