opinion on colder plugs

[tjvdubsport]

i have a 98 GTP with FWI and was planning to get 605 Autolites which is 1 step colder from the stock 606 , will i get a bad fuel mileage ? or am i getting some performance ?

[Bio248]

you dont need colder plugs unless youre going to drop pullies and run more boost. stay with the stock heat range.

[blueguy]

Never hurts but yeah...Autolite 606's or 605's. Not really much difference anyway.

[tjvdubsport]

thanks for the advice