Hey Guys,

I finally got around to doing my plugs. Not to much work for the 3.9, actually about an hour or less and it was pretty much dark when I did them.

I haven't noticed any change in fuel mileage but I have noticed a little bit of a power change, not sure if it's the 3923's or just the fact of new plugs.

I didn't change wires but am going to soon. Just wanted to write up a little review to let everybody know I have done them and if you have any questions about them, let me know.

Have fun!

 

I am getting ready to put some of those in my '01 4.7. How many miles did you have on your old plugs and how did they look when you got them out? I just bought my '01 and it has 85k and I have no idea how old the plugs are so I am going to change them.
I have been putting it off until I do a good cleaning on my throttle body. After the plugs I will move to the O2 sensors and hopefully those changes will help me get a little better mpg. Also plan on putting a K&N CAI on also. I am getting about 15 city to 17 highway right now and am looking to improve that if possible.

 

Not sure what was on my old ones.. I bought the truck @ 70,000 and now it has 105,000 on it so it was at least 30,000 roughly.

I think when it comes down to trying to improve gas mileage on dakota's... only option is to trade it in for a smart car. (hahaha....)

 

I hear you there, I had an Intrepid with a 2.7 and that sucker only got 20 mpg all the time, interstate, city , highway , it didn't matter. It seems to me that most Dodge vehicles don't get very good mileage, however they have more torque and horsepower than a comparable Ford or Chevy.
I guess the reason that I am trying to improve the mpg ( besides the cost of gas ), is that I told my wife it would get between 17 and22 and it hasn't yet (prolly never will ). She just gets tired of me filling up at least once a week.

 

in theory the 3923's are supposed to help gas mileage because they are 1 heat range colder than stock plugs. which means they wont detonate as early and waste fuel. they are also supposed to help knocking (predetonation).

 

You'll have to make a decision... trade the dodge or the wife... I know the dodge won't get any better..

Thanks wink, I forgot to mention that... they did help the predetonation a lot actually. Before I was checking my oil every 2 days thinking it was the oil... Lately even when I first start the thing in the morning... no pinging! WoohoO!

 

The primary value of the Autolite 3923 is to reduce 'real world' ignition timing with their short nose which puts the spark farther from the center of the combustion chamber.

If you are running the Mopar Performance PCM computer
and it has advanced the ignition timing a little too much for one of your cylinders, an Autolite 3923 will stop pinging/detonation in that cylinder
and help the engine.

If the cylinder is not close to pinging/detonation
a longer nose sparkplug design like the stock Champions
or the aftermarket NGK V-Power
will make a bit more hp in that cylinder
as will a bigger gap...as long as the edges stay sharp
so that the spark will start easily at lower voltage.