Have you heard about E3 Spark Plugs? Diamond fire technology for much better spark. The US EPA endorses them, saying these plugs actually make a difference in how the fuel burns, instead of just how long the plug lasts.

I decided to give them a try in my Chrysler New Yorker. Who knows how long the old plugs have been in there, but they have been changed before (Bosch Super Plus came out) and wanted to see what they were all about. They promised a smoother running engine, more fuel mileage, and long life (5 years or 100,000 miles, whichever comes first for warranty).

Hit the jump to find out how they fared with me:

Went to the auto parts store and picked up 6 E3.46′s for my 1993 New Yorker 3.3L and some NGK Plug Wires, cause I tore apart one of the Autolite wires that were on there (the boot came off) so it was time to change them.

Pulled out the old plugs, and replaced the wires one by one. The front three were fine, but the wire numbers didn’t match up with the cylinders on the ignition coil. No big deal I thought, NGK screwed up the labels. (All NGK Plug wires are labelled telling you which cylinder they go on. They were always right before, but not this time.)

I start working on the back three, and they’re proving tough to get out. I get the Number 1 cylinder plug out, and tighten the E3 in. It seems to go in quickly though, so I start the car to make sure it didn’t missfire, and to make sure I threaded the plug in all the way. It ran fine, and was tight, didn’t feel like coming out.

Cylinder no. 3 on the back. Same issue, came out tough, goes in easy, but now I have a problem. Plug wires aren’t long enough. Come on NGK. So I play around with them, switching them around, and find none of them are long enough for the rear. I used two of the old wires to get it to the parts store. Cylinder no. 5 came out easy, and went in easy.

So driving to the parts store, it starts to misfire. Crap I thought, all the E3 horror stories I read on the net are true. I shut it off at a stoplight, and the car’s computer won’t even let me crank it over to start (I guess to prevent damage to the engine.) I push it into a Wendy’s parking lot, and walk the rest of the way. Picked up a set of Champion plugs instead of the wires.

I get back, pull the battery, reset the computer, and the car lets me drive it home. Now i’m hearing a *pssh* *pssh* *pssh* sound, like a Ford Triton engine does when the plug blows out of the cylinder head. The No. 3 cylinder plug in the middle has made itself loose.

WTF am I having all these problems? They’re just spark plugs. I can’t even get the old ones back in the rear, the threads are screwed up. One more walk to the auto parts store to get a 14mm Spark plug thread repair tool, and now I have all 6 E3′s installed. Start the car, and FINALLY, no missfire. Runs pretty smooth, but i’m still skeptical about the plugs. First they caused me a missfire, then fell out, then screwed up my threads in my cylinder head.

Fast forward a day. I’m starting to notice a twitch in the idle at low rpms. Figured I should go get a matching set of wires, because that might be the problem. Got the proper Autolite Pro Fit Professional plug wires, and it seems a little better. In the back of my mind, I believe the car ran better with the old crappy Bosch plugs in it.

Today, the idle twitch is back, and is turning into a vibration. I also smelt a rich exhaust upon startup this morning. Drove 60 km and used 1/4 of a tank. Usually at 60km in the New Yorker the fuel gauge hasn’t even moved from full yet. Screw these E3′s I thought. I picked up some NGK G-Power’s for it. I used those in my Explorer and Stratus no issues whatsoever. Pulled out all the E3′s tonight, cleaned up the spark plug threads with my tap for every cylinder, and the NGK’s go in fine. Reset the computer and start the car. It idles silky smooth and is quiet like a luxury New Yorker should be.

So no, E3′s don’t work for me, and by judging all the posts on the internet (search for “e3 spark plug misfire), they don’t work in cars either. Just lawnmower and two stroke engines like they were originally designed for. My plugs lasted me 60km and 2 days, not the 5 Years and 100,000 miles they say they do. They also dropped my MPG from 20 MPG to 11MPG. A lot worse then my 4.0L explorer that weighs 1000 lbs more and gets 14 MPG consistently.

I’m going to try E3′s in my lawnmower this spring. Someone I know has gotten 75% more cutting from a tank of gas, and the engines don’t bog down with thick wet grass. Maybe these suckers do work on SINGLE CYLINDER ENGINES.

Has anyone tried E3 plugs? Whats your spark plug horror story?