E3.66 Spark Plug

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ITEM # : E3.66
Automotive plug that fits in a variety of import and domestic applications.




E3.66 is a 14mm, 1.000” reach plug with a taper seat. It fits a wide variety of late model applications, especially Hemi applications. E3.66 is widely stocked in automotive retail stores. E3 automotive plugs have three legs securing the DiamondFIRE electrode to the shell. This allows for excellent heat transfer, and helps to create more turbulence in the cylinder. The patented DiamondFIRE side wire is proven to increase power, reduce fuel consumption and improve hydrocarbon emissions in long-term use. The unique ground electrode and full-size center electrode also provides optimal performance for a guaranteed five years or 100,000 miles.

Part Number: E3.66

Resistor: Resistor

Hex Size: 5/8"

Thread Reach: 1.000"

Thread Diameter: 14mm

Seat: Taper

Tip/Gap: DiamondFIRE Fixed Gap Cannot Be Adjusted

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Reviewed by jlmayes
03/09/2020 - 03:50:36 PM
great product
i purchased these for in my FWD dirt track car and they work great i also ran E3's in my other dirt track car last year one full season and not one problem, will gladly buy them again !
Reviewed by mikemid0229
03/21/2018 - 03:35:06 PM
My 05 Jeep Grand Cherokee 5.7 lives e3
Put 16 e3's in my hemi jeep and could instantly tell a diference.. smooth idle, increased gas mileage, quicker acceleration.. big fan of e3 plugs and will continue to purchase the for all my engines, big and small!
Reviewed by Grumpy
09/05/2017 - 04:33:51 PM
Trenton Ryan
Thank you for a great spark plug. 83100 miles over 8.5 years. I started to get a miss. I put my second set of E3 plugs in with new wires in my 08 Jeep Wrangler 3.8L with 92855 miles, it idles smooth I'm hoping to improve my mileage to what it was years ago. I have put E3's in almost everything I own.

The only thing I can say about E3 spark Plugs THEY WORK just as advertised
more power, reduced emissions, improved fuel efficiency, longer life, faster starts