I'm running the E3 plugs in my '11 and it's hasn't thrown any codes. I put them in 2012, so about 1yr ago.

 

"Designer" spark plugs are a joke. The JK 3.8 doesn't seem to like anything other than than the OE plugs.

 

Totally true, stick to OEM plugs, and yes the "tornado" in your intake pipe doesn't work either!!!

 

I refuse to put any of those SPECIALTY plugs in any of my Jeeps.

Many years ago I tried a set of the newly released designer spark plugs similar to the E3's that are being produced now. The '98 4.0L didn't like them at all. Tried numerous times to return them with a letter to the manufacturer; they kept insisting to send me a new set. No matter how many times I refused the new set; I just want my money back and they wouldn't do it.
A year or so later without notice; I received a set in the mail and customer service claimed they new nothing about it.

Finally gave them away to aa guy in need at a local off road event.

 

I put one in my weed eater and it ran like crap. Tossed it and got a factory plug. No issues.

 

I run them in my lawn mower and can mow twice as much between fill ups and my mom run them on her 04 mustang amd went from 24 to 27-28 mpg. I however ran them on my hemi and the hemi ate prob 6-7 of them. Put ngks back in never a prob after that. Chrysler(fiat) products do not like platinums or fancy things just good ole reg ngks. Thats What all the 11 second hemi trucks are running

 

X2. Run the OEM, and run away from the e3's. They are terrible.

 

I ran the E3s for about 9 months in my 3.8. I did get the increased power and mileage they profess for a bit but then they just started breaking at the insulator. In all I had 4 break in 9 months. Switched back to OEM platinums 30000 miles ago and haven't had an issue since.

 

i ran them in my 2004 gmc sierra z71. it accelerated smoother. not more power feel just a smoother feel. then one burnt out in about 10,000 miles and put a factory plug to replace the one that burnt out. overall i wasn't impressed. i also replaced my wires with some nice ones that summit offered. i don't know if it was the plugs or the wires or both that i got the most benefit from.

 

I had them in my 07 Saturn Aura and one of the plugs burned up in less than a week causing a cylinder misfire. Took em out and replaced them with champion iridium, and the cars been been fine since.