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Thread: E3 spark plugs

  1. #1

    Default E3 spark plugs

    Has anyone tried the E3 plugs? Summit has a mfg. Rebate for $3.00 off per. Not sure if they are worth trying.

  2. #2


    Honestly, my experience with E3's are in sport quads, I had aquad that was a little fat on the big end and I was ready to rejet. I swapped plugs to get a good clean read, went with the 33 and ended up not having to touch the Jets. They clearly do something.
    1984.5 G.T.350 had since 16y/o
    95 Cobra, Crystal White

  3. #3


    don't waste your money.
    They are garbage.
    Stick with Motorcraft or autolite copper plugs unless you run something exotic. They are cheap and work the best for these motors.
    I believe stock are autolite 25 or Motorcraft Asf32

  4. #4
    FEP Power Member Mikestang's Avatar
    Join Date
    Aug 2013
    Firestone, CO


    What Mikestang63 said

    Sent from my LG-LS997 using Tapatalk
    1986 Ford Mustang GT-

    Not much stock stuff left
    347 NA power, CNC ported heads, Extrude honed Trick Flow Intake, Custom Cam
    Suspension, custom k- member, TQ arm/pan hard rod... Much more
    Restored and ready to race, made to go fast while cornering

    1981 Mustang GT-

    Old SCCA A-Sedan National Champ car
    In the middle of rebuild

    1986 LX Sedan-

    Plans to be determined...

    "Every day I learn how much I don't know"

  5. #5


    E3 Plugs = Snake Oil

    Also, I had problems with Bosch Platinum plugs in my 85 GT. For some reason that engine didn't like them.

  6. #6


    I saw a set come undone and drop several peices in the engine on a mark7 when i was in high school taking auto. Could have been a newbie installing them wrong though.

    I remeber an add that was hanging up in a ford museum for autolite spark plugs. It had a picture of a ford gt and said "we've spent thousands of dollars and hundred of hours testing to make the best spark plugs for our ford cars, thats why we run the same spark plugs at lemans as you do".

    Kinda stuck with me
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  7. #7


    I've run a lot of NGK plugs and will continue to. Like I said, my only experience with E3'S is in sport quads. The machine does like the plug and I won't hesitate to run another one. 8 of em is a bit pricey, the gamble is yours. Spark plugs, motor oil, air filters... Everyone has their own opinion. I've personally seen Autolites come apart and destroy an engine but I know race engine builders that swear by them. Choice is yours.
    1984.5 G.T.350 had since 16y/o
    95 Cobra, Crystal White

  8. #8


    I had a set that came in an 5.0 HO engine that I bought for a spare. I took them out to look at them and they appeared new. For fun ,I put them in my Cougar and the idle cleaned up. Maybe the old plugs were weak but relatively new. I also run an Accel coil which is a relabeled Jacobs Pro Street coil. I'm not endorsing them, just sharing my experience.
    84 Cougar, 88 HO with 700DP, Edelbrock RPM intake, 1.7 RRs, shorty's and SS exh, T-5, KC clutch, Hurst pro billet, line loc, 8.8, 4.10s, suspension mods....blah, blah,blah.

    71 Comet, 289, Liberty TL, 9", 6.00s, 11.9x @ 112.... blah, blah, blah.

  9. #9


    E3 will likely go the way of Accel U groove or Splitfire eventually. We just don't see much of them.

    My Dad is running one piece E3's in his 4.6L 2006 Mountaineer instead of the two piece breakage problems autolites on the tritons are notorious for. It seems to like them as it picked up a few MPG. But last I checked swapping plugs for new ones gapped properly usually yields mpg and power too.

    Horsepower TV did a dyno session with E3's. The test mule was a SBC and it liked them. The test showed the motor ran much cleaner when measuring emissions and the dyno showed it made more power.

    They did show less advance was needed for complete burn though too -- so stay conservative on advance or you'll really need to watch it.

    If someone gave me a set I don't know if I'd run them. I like the way it's always ran with factory plugs.

  10. #10


    Quote Originally Posted by Mikestang View Post
    What Mikestang63 said

    Sent from my LG-LS997 using Tapatalk
    brotha from anotha motha!!!

  11. #11
    FEP Senior Member
    Join Date
    Jan 2011
    Vancouver BC Canada


    I would take any claims made on automotive TV shows or many car magazines with a grain of salt.When a company is spending big bucks to advertise their products in these magazines or on these TV shows, good bet that the magazine/show will go out of their way to obtain positive results for their advertisers.
    1978 Fairmont 2 door sedan, 428CJ 4speed. 9.972ET@132.54mph. 1.29 60 foot
    Replaced the FE big block with my 331/4 speed in my Fairmont, best 10.24ET @128 MPH.
    1985 Mustang LX hatchback NHRA Stock Eliminator 302 4 speed best in legal trim 12.31@107 mph, but has gone 11.42@115 with aftermarket intake, carb, and iron Windsor Jr. heads.New for 2012! 331 cube SB Ford, AFR 185 heads, solid flat tappet cam, pump gas; 10.296ET@128.71 mph, 1.37 60 foot.
    1979 Zephyr Z7, all original 302 auto, 2nd owner.

  12. #12


    Or they don't tell you the down side....

  13. #13


    I don't have any evidence one way or the other. I just took the word of the guy at my local Dyno shop that I use as the truth. He keeps a stock of the plain .98c (or whatever they are these days) Copper Autolites. It's not uncommon for cars to start stumbling on the dyno and he just throws in a set of the #25 (or whatever they call for) Autolites and knows he doesn't have to worry about spark after that. I mistakenly installed a set of the platinum Autolites cause for some dumb reason I thought that would be better when I took it there. He saw that and made ME change them out, LOL. He said "Who would want a spark plug that supposedly lasts 100,000 miles in their car?" I got it after that. All that was done so they could brag about miles in between a service because it sounds good in a sales ad.
    Last edited by homer302; 07-26-2017 at 04:52 PM.

  14. #14


    A good friend is a fuel economy engineer for an auto company, and I asked him about these types of spark plugs. He told me they made no difference when they were tested. Also, he mentioned oil additives. In some cases oil additives actually increased engine wear in their testing. Anyway, he told me that they don't work. His department spends millions of dollars to gain .1 mpg increase in fuel economy. If these actually delivered more power or increased efficiency they would be used as OEM equipment.

  15. #15


    Put a set in a friends 91. Mostly stock bolt on car. He said the difference wasn't significant but he said fuel economy was a little improved. Like I said mostly stock bolt on motor

  16. #16


    Id say 90% or more of fuel economy is how you want to drive. If you are expecting an increase in mileage, without even realizing it you will do better.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  17. #17


    I put a set in when I had my 86 GT, after about a month it would stumble when driven hard so I replaced them with regular autolites, didn't have an issue after that.

    Sent from my iPhone using Tapatalk

  18. #18


    My brother put some in a dirtbike. Within the first hour the electrode broke and broke the piston. Was expensive enough to fix a YZ250 2 stroke. A car is a whole 'nother animal. I won't run Champion either for the same reason....had electrodes break and fall off. We run Motorcraft plugs in our methanol injected Buick 455 back in the day. I pretty much run Motorcraft, NGK or Bosch.
    1985 GT, Sunroof, 5 Lug, Rear Discs, 01 Graphite Bullets, 88 forged piston shortblock, 2.02/1.60 Alum heads, Weiand Stealth, Holley C950 TBI, BBK Long tubes

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