plug question., slowly shrinking gap? Options

[Bitter]

i KNOW i had all 4 of my plugs at .8MM about 6 months ago. i regapped them the other day and 3 were at .65-.75MM with one still at .8MM. is this within normal bounds or is something awry? i can tell when the gaps are getting out of whack, i get slight misfires at an unloaded idle.

the plugs read as my combustion temp being a little high but not out of a 'normal' range. i expect this from my timing advance, but this slowy shrinking gap has me a little concerned.

[LewFX]

i thought irridiums are far better than standard..im too lazy to look in my manual about this, ill try a google search

[Bitter]

i thought irridiums are far better than standard..im too lazy to look in my manual about this, ill try a google search

irridiym and platinum plugs just have a longer service life, in the 7afe and 1zzfe/2zzge you have to widen the gap because you get a weak spark between the points. this is because the sharp point conducts too well and the needed potential isnt reached with the stock gap.