I've got a 2002 Civic LX 5sp and am getting great gas mileage, but it's time to change out the plugs at 110k, so checked at the auto parts store and they must of had a dozen choices that would replace my stock plugs. I understand my stock plugs are the long life Iridium plugs that cost 12.75 to replace each which I have no problem putting back in , but was wondering if any body has experience with some other choices like the Bosch Platinum's, Denso or some of the other NGK choices. Did your MPG increase, stay the same or get worse. I mostly looking for a plug that might increase my mileage, the long life plugs are nice to have , but changing plugs out on my Civic is so easy and think it's a good way to check the health of my high mileage Civic ever so often. Thanks for any advice.