E3 Spark Plug initial review for 92 XJ 4.0
 

Saw these on rockauto for cheap and decided what the heck...model number was E3.58.

Replaced the champion plugs that were in yesterday. Initial impressions:

Cold start in 3 cranks, warm start in 1
Idle is just as smooth as before
Throttle response is slightly better, feels more eager to rev
WOT acceleration to 40 definitely better, consistent 0.3 second difference on the phone app.
Cruising rpm to maintain 35mph flat road is slightly higher by 50-100rpm

Based on my initial experience, I'd venture that the plugs make a little bit more torque, but a little bit less horsepower...I'll report back on any changes to MPG.

junk !! I installed them in a hemi dodge , after 1 week had misfire codes and stumble I could not figure since I just did a full tune up . ended up at the stealership for diag and found out the plugs wer garbage put a new set of ngk plugs in and all is well , I recommend staying away from gimmicks like these ,if they wer that good or made more power the factory would use them

Lee, you should post your pics of the ones from your 2.8...

From the research I did online they seem to work well for some, terrible for others. At $2 a plug I figured I'd be a Guinea pig. Maybe they have quality control inconsistency?

I have seen cases where the electrodes will fracture and break off!
Probably rare but still kind of concerning.

Next time just run NGK's. Made in USA or Japan, cheap, and great plugs.

How long did you monitor performance with the Champions before the switch to E3? And how old were the Champions before the switch? You would get a better idea of just how much more the E3 actually give you.

Champions were put in at 90k (99k on odometer right now), all were gapped to 0.045. Previous mpg on those was 17.2 average over 3 tanks.

Just did my first full fill tonight with the E3s and I got 16.9mpg...we'll see after a few more fills if it hangs around this or not though I will say the entire tank was city driving where the other three tanks were a 80/20 mix of city/highway. More updates to come.

I use the cheapest champions you can find and have had no issues. The second set came out with over 100000 and i could not believe the xj ran as well as it did with 1/2 the electrode left.

Why gapped at .045?

Switched them out for new copper champions, again gapped to 0.045. Recently (after 5,000 miles on the E3 plugs) I noticed reduced MPG and power (10.2 MPG, 1600rpm to maintain 35mph, before was 1500rpm)...after switch back to Champions, it's only 1350rpm to maintain 35mph, too early to tell on MPG.

oh yeah, gapped at 0.045 because the stock coil can handle it, no detonation or stumbling, throttle response better, etc.

So, gapping your spark plugs to the spec of a worn out plug improves performance?

There is thread here:

https://www.jeepforum.com/forum/f11/...5-ats-1551782/

They talk about using a larger gap with better ignition parts to improve gas mileage

So I posted that every year I pull my plugs to give them a look and regap to .035 as necessary. Now I have an '00 with the coil bar. So I was told that was not a good thing. While most of the time stuff I read goes over my head, this time being no exception, here is what I think they were trying to tell me.
The gap on plugs increases with use. Putting them at .035 it is assumed that this gap will increase with time to a gap that is actually better and will not be so bad at 30K when you should replace the regular Champion Copper Tops I use.
I know I am explaining this poorly but hope that it still gets what they were saying across.
They suggested to me that because I pull them every year try .040.
I was thinking that I would try this in April. Which is when I check plugs.
But cruiser54 seems to not agree with this.
When cruiser speaks I listen but would be curious as to what he thinks about this logic.

Then why does replacing old plugs at .045 with new plugs at .035 give a noticeable change in performance?
The insides don't really wear out. The gap just gets bigger.

Iridium plugs were made so they could go 100,000 miles before changing them. Why did they bother making plugs that were way less prone to extending their gap throughout the plug's life?

If I convert an old CJ7 to HEI distributor from the crappy Motorcraft original system, I increase the plug gap to .045 because that suits the HEI. It's way more powerful than the Motorcraft system and .045 is what vehicles with HEI have for a recommended gap.

To be frank I did not fully understand the logic behind some of this. Stuff on the internet. Who knows? They did say what you said about running a more high performance ignition system using a bigger gap. If you feel like wasting some time you can read from here for a few pages.

https://www.jeepforum.com/forum/f11/.../index253.html

Most of the conversation of running the bigger gap is there.

Since I do this yearly figured I would try the .040. But of course you have me rethinking it. LOL.

While I did find the thread somewhat informative. The only thing I did was swap over my diffs to a synthetic. I was going to drain and replace anyway when I first bought the Jeep just to know that it has been done. Figured why not on the synthetic.