So from what ive read the iriduim plugs do in fact last longer than a standard plug and can sometimes help an engine start easier and whatnot. Since the 9 is a colder plug than the 8, will it help lower the engine temps at all? Maybe 5* or something? Ive also heard that it can improve low end hit a little and not foul plugs quite as easily. My main question is; Will i notice any difference in temps, stalling in low rpm 1st gear stuff, or better low end? I understand that any improvements will be very minimal and nothing drastic, but i figure all little benefits can add up. Thanks guys, bill804.