i just took out my iridiums @ 100,637 miles, i did not re-gap the plugs at all in that time.
the gap did open up but i did not get any loss of power or MPG(tells you how good the stock coils are).
the iridiums do provide a better spark at less volts than a standard plug, just read the ads on
the Denso or Ngk web sites. i will bring the old plugs to WCBF '07.
i did get a high RPM(over 5000 RPM) miss the last 100 miles but just on
one cylinder, so i changed all the plugs. i could have fixed the gap on the old plugs
and put one new plug in and be good to go.
the center electrodes look like new on 5 of the old plugs.
old technology vs new technology, i'll take the new technology.
i won't get into the extra power thing, but if you get a better(hotter) spark
at the same volts then thats a good thing. back in the mid '70s my drag car
put out 16.5 volts just to get a hotter spark(plug gap no more than .040)
i woud burn up my plugs(side gap) in 2 or 3 meets and that is with 40 or 50,000 volts.
that is a standard '70s plug that i made into a side gap plug.
GOD I HATE TYPING