Gapping Autolite plugs

cjman15

Banned
Apr 15, 2004
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Fairfield, PA
I'm gonna be puting some new plugs in my car soon and I was wondering what you would recommend for gapping these plugs. They are Autolite Platinums and my engine is completely stock... I've heard from .45 to .50 gapping... what do you think
 
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cjman15 said:
I'm gonna be puting some new plugs in my car soon and I was wondering what you would recommend for gapping these plugs. They are Autolite Platinums and my engine is completely stock... I've heard from .45 to .50 gapping... what do you think


Return them and get Autolite 25's. They are copper plugs and what you should be using on your Mustang. Platnium plugs have no performance benfit at all despite what everyone things.

Stock gap is 0.052" - 0.056"
 
My 82 gt said stock gap is 42-46, and it really wants it in thouse ranges. I had one at 50 and it ran rich for a while. I replaced the set and put them all at 44, and I never had a prob. Before in my vick i never even gaped them and never had a prob. The stang seems to be very touchy.
 
TFI ignition should be .052 -.056, as said.
i dont know what duraspark, etc ignition use. gap it too wide and you overwhelm the coil's capacity.
 
cjman15 said:
why are tha copper plugs so much better than platinum
copper plugs (annealed) conduct way way better than platinum. plats are nice for cars that have inaccessable plugs - plats dont experience gap erosion cuz they are hard (and dont conduct very well). think of tires: do you want really hard rubber that does not hold the road (but lasts forever) or some nice grippy skins that hold like on rails, but wear out sooner. i choose the latter.

also, ive had plats break long before they would have worn out (i know Mike has too). how long does one really leave plugs in there?

on 4th gen+ camaros, plats are nice cuz it takes two days to swap plugs.

also, some 5.0's have experienced a lowered idle and higher RPM miss (~4K rpm) when running plats.

iridium is kinda the best of both worlds, but is really pricey (nice for nitrous and/or forced induction).
 
Platnium = Crapinium.



I've had a few Autozone/Pep Boys employees refuse to sell me copper plugs for my car stating "For high performance cars you shouldn't be running anything less than plats. I'd recommend these Bosch +4's" :rolleyes: :nonono:
 
hey, ill also add that for those who end up using a plat plug at some point: you cant gap a plat plug - or be very very careful doing it. using a conventional gapper will scrape the coating off. funny, since every plat plug ive ever bought was the wrong gap.
 
I like the cheap plugs because you can modify them, put them in and beat on em, and change em frequently so you always have good plugs in the car.

Platinum plugs are more of a maintenance-free deal, you can't screw with em but they don't wear out too fast either. Also Bosch's 2 or 4 ground open design makes for cleaner combustion and improved gas mileage, at least in certain engines
 
Ray III said:
Also Bosch's 2 or 4 ground open design makes for cleaner combustion and improved gas mileage, at least in certain engines
please elaborate. IIRC from high school physics, electricity takes the path of least resistance. one ground strap should do it.