Hey all, I just wanted to share a great $$$$$ saver for you. I changed to Autolite Doulbe Platinum plugs and Autolite Professional wires. Guys, these things are hot! I won't be putting anything else on my Ranger. And for $4 a plug and about $30 for wires you can't beat it. And just a tip, if you have the EDIS system and use single platinums, you are wasting your money. With the unique firing of an EDIS single platinum causes EXCESSIVE wear on the plug. Do it right, do it once.

 

I put the Autolite DPs in my 3.0L as well.

I can also tell you that they work good in the 4.0L OHV.

 

Just a quick FYI: AutoZone carries Motorcraft spark plugs at about half the dealer's cost.

 

From what I have been told Autolite makes the plugs for Motorcraft. So buy which ever is cheaper. And yes Double Platinum is the only way to go with the EDIS systems.

 

Interesting. I just heard the same thing, myself. That's probably why so many people have had good luck putting Autolites in their Ford motors. I've been hanging around the the Ranger Forum for a while and like I said a lot of guys have installed the Autolite DP's in their 4.0Ls and have reported very good results.

 

Honeywell actually makes Autolite, and Motorcraft plugs!!!

If anybody is interested, e-mail me at:
and I'll send you the coilpack schematic I made up. You can
see how a plug in each bank gets the opposite polarity spark.

That's why it is important to run double platinums, because the
outer electrode will erode in one bank, while the center electrode
wil erode in the other bank.....They also fire on every rev. of the crank,
twice as often as will a conventional ignition....

 

I'm not sure if i have the edis system. All that i have is a distrubtor and no idividual coils. So would it be just as good for the disributor system to use a platinum plug or go the extra yard for some of tose Double Plaitnums

 

John,

No, with a distributor, you don't have EDIS, and you don't need
double platinums....

 

As I understand it (with the help of you guys), the DP's are built to handle the extra stress that an EDIS system puts on the plugs. I notice you can see the difference in the electrodes b/t the double platinum and single platinum.

So heres my question: do the different plugs make different sparks which would matter performance-wise?

Or is the issue only about how much longer the DP's will last verses the SPs?

 

Rock,

Good question!!

One thing to keep in mind, it isn't a "stress" thing with the EDIS,
it is a spark polarity thing with EDIS that requires both spark
plug electrodes to have platinum. In the case of a conventional
ignition (distributor), ALL the plugs get the same polarity spark
which will erode only the center electrode.

I hope this answers your question!!!

 

Thanks for the reply Bob. Things are getting clearer.

I saw this opinion on the exact same subject posted at another Ford site, and I think it's worth positng here:

"My 2cents worth:

The platinum is in there for LONGEVITY, not to make any difference whatsoever in spark quality.
Barring base engine concerns or fuel mixture concerns, dual platinum plugs WILL last 100,000 miles.
99.9% of the platinum plugs that I've replaced at 60K services showed no wear and no excessive gap between the electrodes.
If you take the name brand off, Autolites and Motorcraft are the EXACT same plugs.
Bosch, NGK, Splitfire, Quadfire and Champion plugs cause misfires, rough and lopey idles, and poor fuel mileage - And it really bugs me that I can't explain why that is - it just is.

--------------------
Former Cal Worthington Ford, Korum Ford, Harnish LM, Renton LM, Evergreen Ford, Fugate Ford, Prestige Ford, Pearson Ford employee."

 

Bob,
I took a look at your schematic, nice job, btw. I was wondering, if this is the scheme that is used, would it be beneficial for plug wear to take the plugs out and swap them to the other side at half the plug life to promote even wear on both banks?
Thanks again,
Jim

 

Hi Jim,

What you are suggesting would extend the life on single platinum
plugs. One thing to notice, however. If you pay close attention to
the OEM Motorcraft plugs, they are single platinum!! But, the plugs in one bank have a different letter suffix in the P/N than the
plugs in the other bank. This is because the outer electrode is
platinum on one plug P/N, while the center electrode is platinum
in the other plug P/N.....So, if the plugs are pulled, and
re-installed, it's important to put the plugs back into the same
bank that they came out of.....

 

Bob, thank you for solving a riddle for me. I had always heard about the factory plugs with the different #s and how it important it is to put the OEM plugs back in the same banks after checking, etc. And I had always wondered why that was.

And Jim, good question about the mid-life plug swap scenario

 

Rock, you had a post about NKG, Splitfire, Bosch, etc...... causing misfire. There is a very simply answer. All the plugs you named, have one thing in common, V center electrodes. Just as a DP plug is excellent in EDIS, the V plugs are just as bad. I am not sure as to the cause of this phenom. As a marine electrician, I have a theory that the V under extreme heat, wear, and compression may actually create a slight voltage drop across it. I have no way to prove this. But it makes perfect sense according to electrical theory. Anybody want to second this idea?