Looking for some suggestions on spark plugs for Mazda speed protege ... Car currently has Silicone hot pipe cold pipe , injen cold air intake , new egr valve , boost gauge ....any tips are helpful . Thanks
But your answer is NGK PZFR6F stock # 6876. Those are the proper and *BEST* plugs for the MSP, but they're also a little pricey. For a bit less money you can get the NGK ZFR6F-11 but they will need to be regapped to .032".
I'd personally get the PZFR6F's and do it right. You only replace plugs once every couple years, if that. I've personally used the ZFR6F-11's for a really long time now with no issues, but what's also cuz I didn't know any better. Next plug change, I'll be going to the PZFR's. RockAuto has the best price on them, they're like $11 a plug as opposed to $15+ from everyone else.
Oh and some will also claim that Iridiums are better, which would be true if you could find NGK Iridium plugs with a proper gap. Regaping Iridium plugs is a bad idea too, you'll end up damaging the electrode and wasting precious time and money.
