E3.66 is a 14mm, 1.000â€ reach plug with a tapered 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 a full-size center electrode also provides optimal performance for a guaranteed five years or 100,000 miles.
Part Number: E3.66
Hex Size: 5/8"
Thread Reach: 1.000"
Thread Diameter: 14mm
Tip/Gap: DiamondFIRE Fixed Gap Cannot Be Adjusted
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 difference.. smooth idle, increased gas mileage, quicker acceleration.. big fan of e3 plugs and will continue to purchase them1 for all my engines, big and small!
Reviewed by Grumpy
09/05/2017 - 04:33:51 PM
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.Â
The only thing I can say about E3 spark Plugs THEY WORK just as advertised