even spending hundreds of millions
the automakers R&D departments go a whole year
and then feel lucky
if they get a 1% improvement in fuel efficiency from an engine
... not just Chrysler
... but Honda/Porsche/BMW have testified under oath before the US Congress that 0.8% per year improvements is the best they usually can achieve 'all out'

if you can get 1%
by indexing your spark plugs
I suggest 'go for it'

an race engine builder who can get a 1% improvement
over his competition
can usually convince the team owner
to spend big money for the advantage

how can you tell when someone is telling you the truth about improving engines?

the guy who gives suggests several mods that together gain a few percent each
is telling the truth

the guy who says he gets 5 MPG improvements
(over an average of about 15 MPG)
is either deluded
or does not know how to do a reliable MPG test,
or just lying

 

take your time. use a good washer in your spark plug socket to keep the plug from falling out. while taking the one of the back ones out the plug fell out and rolled under the intake manifold. i could not have done this if i tried, but instead of gettting a magneticgrabber i pushed it outof reach. i eventually got it using oneof those camera snakes. i understand thinking what an idiot, but another guy did it as well.

good luck.

 

I didn't realize we were talking fuel efficiency/mileage. I was under the impression the conversation was about performance gains. Either way, if you want to spend the time (ie: pain in the ***) to index plugs that won't give you any enhancements at all, be my guest. It just won't be advantageous...in my opinion.

Like I said, I wasn't trying to bash, just giving some advice that originally came from an engine 'expert'.

Oh yea, and one other thing. When did Chrysler ever become concerned with fuel mileage? lol

 

I just changed the plugs on my 07 ram qc 5.7 4x4 yesterday. It took me about 45 mins. Everyone talks about how hard it is. It is not hard at all. Use a 5/8 spark plug socket a 3" extension and a u joint. thats all i used. I had more trouble getting the coil packs off than changing the plugs. Also that morning I put a magnaflow cat back exhaust on. I put champion plat. plugs in it. Model number 3570. Between the two of those mods I dropped my 1/4 mile time from 15.11 (adverage) to 14.48 (adverage).

 

I did my 06 3.7L dakota about 2 or 3 months ago. I agree, it was a breeze. I usually dread replacing plugs on a V6 or V8, you never know what sort of clearance issues you may run into. But with these engines, its like changing plugs on a 4 cyl.

The only tiny issue that I had was my craftsman sparkplug socket rubber gromet gripped the spark plug way to tight, so after installing the new plug, the socket didnt want to let go inside the chamber, lol. So I just trimmed my grommet in half, So it JUST holds.

It was a 30min job.

Next on the list was my fathers 04 ranger with the 4.0L. Man....does that engine JUST fit in there. The last 2 rear passenger side plugs required the wheel comming off, removing the wheel well liner, and busting a few knucles.

We are so lucky.

 

so did you guys reset the cpu after changing the plugs?
It's probably a good idea to just disconnect the neg. cable before I start.

 

I just changed mine over the weekend. When it was new (a few hundred miles or so), I put the 3923's in. The idle was smooth, but I had lost my low-end power and a few points on my MPG. I didn't have this issue with my '06 with the those plugs, so I can't explain it.

I went back to the Champion crap-o-la's after a few hundred miles and now with 13,700 I have changed to the Autolite 5224's. I am very glad I did and I am very happy. With the 5224's, although they are OEM "equivalents", the idle is as smooth as the 3923's and I have not lost any power plus I have gained a few points on the MPG.

Regardless if you go with the 3923's or the 5224's, stick with the Autolite's and toss the Champions in the can. They absolutely suck ***!!!

 

My gut has been telling me not to go with the 3923's. After hearing this I think I most likely won't. Thanks for all the input guys! This really is a great forum, and I appreciate it!

 

a 3923 spark plug installed with a small 0.020 to 0.025 gap
is a good plug to try
in a cylinder you have already diagnosed as pinging

for cylinders that are not pinging
go with an extended nose plug design with a big gap

your V8 has eight different cylinders
and you must expect that they vary,
typically by about 8%
according to automaker official tests reported in the
Bosch Automotive Handbook

 

Saw it mentioned earlier in the thread about using anti-seize on re-assembly. I am planning on using (Nickel Anti-Seize) when I do mine. I have a tube of MOPAR part#05012249AA that withstands 2400F. Probably pretty good insurance regardless of what plug is chosen. Blowing the hole out prior to plug removal is sound advice as well.