Well having never been happy with the idle quality of my 3.9 V/6 Dak and in a seemingly constant quest for improving it I have tried numerous plugs. Autolite 3923, Autolite Platinum 5224, Champion 4051 (truck plug), and factory recommended Champion RC12LC4. I have mixed Sea Foam with the gas among other fuel injector cleaners and ran Sea Foam in the crankcase even, thinking maybe it was a lazy injector or maybe a sticky lifter. I just put Autolite 3924's in it and it now idles silky smooth, runs crisply and on a certain 1/3 mile grade which normally calls for the transmission to downshift, it pulls nicely in O/D.

This engine has always seemed "cold blooded" as if it never truly warmed up and while the temperature gauge still reads in the lower third of the normal range the performance does feel much better. Now I'll see if the mileage improves as well. I got 18.3 on my last trip of I'd say mixed driving. About half interstate and the rest 2 lane highway and blacktops in very hilly terrain with "spirited" driving I like to call it.

 

That isn't going to last for long, Autolite plugs just don't last, their like an economy plug to begin with.I sell auto parts to begin with for better performance you need to use a platinum or iridium type plug or myself I've been using these E3 plugs in 97 Ram with a 5.2 and gained 4 mile to a gal. and have a way better performance and no rough idle.

 

I think you picked the wrong place to try selling that load of horse manure. I and about anyone on here will guarantee that changing to E3's aren't going to gain you 4 MPG unless that '97 Ram still had the original plugs in it.

I tried the Platinums and they performed no better than any other plug. They just cost $3 apiece instead of $1. Sorry Rev. but spending $7 a plug to put in a pushrod V/8 pickup truck is just a waste of money. IMHO

 

Ya platinum is a waste, least for our trucks. Im VERY happy with my autolight 3923's. Tho with my plenum leak its a very different circumstance lol.

Deffinatly let us know what happens

 

Almost anyone in here will tell you our motors for some reason run the best with autolight's 3923's. Im sorry but paying 64.00 for 8 plugs is nuts(hell I paid less for plugs,wires,cap and rotor) I paid 15.00 for all 8 and my truck runs better and not to mention a cheap fix for performance.

 

Sorry you all feel that way,I don't offer advice unless I find something that works,I know they are high dollar plugs.And believe or not certain things you use do make a difference ,I've been wrenchin' on cars for most of my life, and sometimes you got to spend the money to make it right.And yes it does make a difference on plugs and you don't think so ,your clueless ,sorry I'm just straight forward about things.By the way Autolite is a cheap Ford plug a cheap version for Motorcraft plugs ,Like I said before I do work in auto parts ,see people throw them Autolite back at me everyday and ask me what I recommend and trust me I don't recommend most expensive plug out there,My thought is fix it right the first time and you won't have to ponder what to do with it next.You all have to understand that sometimes running the right stuff with make things run better and wrong parts can really set all those sensors off and make it run pretty poor and it may not set check engine light off.Wrong plugs can send a bad message to the TPS (throttle position sensor).

 

Yes true that not all cheap stuff works out but what I am saying is almost every single person in this forum runs autolight and all of them are happy and have no problems with them so why should we have to waste money on a more expensive plug. Think of it this way ok so what if the autolights arent as good as the e3's all I know is I can change my plugs 4 different times(32 plugs) and and still come in 1.00 less then your 1 time buying plugs

 

Whatever works for you man. I'm just saying that the Autolites are a tried and true plug in the Magnum engines. It's a simple engine design and does not need exotic parts to keep it running right. They are just unnecessary unless the engine has been highly modified and in most of these cases Autolites will still be the plugs of choice. As long as the plug gives a good spark and the combustion complete there isn't much else they need to do. The Magnum engine just runs better on them than the other brands most of us here have tried. I have heard of NO problems related to running Autolite plugs and throwing codes or creating other issues. My problem was just a heat range hotter plug to make the truck run a little more cleanly, no codes or other issues, and this one is doing the trick. $1 apiece and issue resolved, simple.

 

i just did my plugs and had a question. i did search alot.
most people used either the A.L. 3923 or 5224.

i had no issuses with mine just thought 90k+ was bad. (.025" off)
i used the 5224 copper cause they were the same heat range.
i don't have a heavily modified motor, shouldn't most ppl go with these?
unless they have issues w/ "the engine has always seemed "cold blooded""

 

4.7 is a different beast. I would use the oem sparks for the 4.7 but for the 3.9,5.2 and 5.9 3923's are the ****. I like ngk v powers. I have yet to try a colder setting Which Is something I think I want to do.