Spark plug gap

[AgtX]

Ive bought some NGK BKR7EIX & it says the gap is 0.6mm, the Nissan service book says 0.9mm, does this matter too much or should I gap it up?

I already have a set of these in my car, had no problems & I know the gap grows as the plugs wear but would it run better or anything with the recommended gap?

 

[Auss15]

I gaped mine, and I have the same plugs, at 0.8mm...06mm I think is a bit small for optimum spark, especially higher boost and RPM..

 

[AgtX]

I gapped them & it ran funny compared to before, it felt hesitant at times just driving at 40 or whatever so I bought another set & didn't gap them & it runs smooth again!?

It ran smooth before with those plugs, thought it would be better with the adjustment but I found its not. I read that you shouldn't gap iridium plugs, perhaps I damaged them somehow when I gapped them, looked ok though.

 

[dread]

I'd always been told not to gap iridiums. The service manual will be talking about normal platinum plugs

 

[CMR]

Dread is correct. Iridium are pre gapped and do not need altering.
Are they worth the extra money considering they don't last very long? Well that's a different story!

 

[Auss15]

I found no benefit from the Iridiums, except to the part retailer.. Ive actually gone back to cheaper copper plugs and find they work perfectly, might not last as long as Platinum or Iridiums but they are much cheaper