loos of power

i recently changed my spark plugs from the Denso Iridium to the recommended Denso Double Platinum... now unless something else is acting up here ....i think the Iridium gave me a lot more Hp than the Double Platinum... any thoughts on the that?????

 

^^^^That.

Always, always gap your plugs. Never trust "Pre-gapped" plugs.

 

There will be no difference in power or MPG between copper, platinum, or iridum plugs.

There very well MAY be a loss of power when running the current crop of multiple-electrode whiz-bang flavor of the week plugs that the tuner kiddies rave about.

Platinum and iridium plugs are more resistant to fouling so they last longer.
That is the ONLY difference. They were developed to allow longer intervals between service, which lowers the "cost of ownership during the first 3 years" which looks good on the JD Powers reports, since most people won't hit 100k within 3 years... that's a significant difference on the reports.
But the plugs cost 3-4x as much so there's no savings in the long run.

 

Id a do a compression test while you have the plugs out to recheck the gap.