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4.6 FLEX FUEL : SPARK PLUGS? what kind.

26K views 11 replies 6 participants last post by  Bert 
#1 ·
Hello, I wanted to put new plugs in the car. It is a flex fuel and I had found it to use Motorcraft AGSF-22FM1. I dont plan on using the other fuel, just regular fuel. Does it matter if the plugs are plat or iridium/plat plugs. I found two autolite plugs at walmart that were AP104 and APP104. I would think these would work just fine. Any recommendations? Does anyone know of a good crossreference site for spark plugs?
thanks.
 
#2 ·
Either use the plugs described on the emissions label under the hood, or call you local dealer for any revised specification. Gas stations all use blended fuels now, so your plan is moot - you'll be burning whatever they sell, which will undoubtedly include some ethanol & methanol. That's what Ford expected when they chose the plugs for your car, so that's what you should install.
 
#3 ·
Sticking with OE plugs is a wise decision. I wasn't too enamored with the Motorcraft plugs in my V6 Taurus and had them replaced for some mid range Champions. Now I run NGK and they seem to be performing the best out of all! This V6 isn't an FFV engine either.
 
#4 ·
Hello, I wanted to put new plugs in the car. It is a flex fuel and I had found it to use Motorcraft AGSF-22FM1. I dont plan on using the other fuel, just regular fuel. Does it matter if the plugs are plat or iridium/plat plugs. I found two autolite plugs at walmart that were AP104 and APP104. I would think these would work just fine. Any recommendations? Does anyone know of a good crossreference site for spark plugs?
thanks.
Mercdriver - I have the same question concerning my flex fuel 2011 Town Car.

The service manual specifies two plugs: AGSF-22FM1 with a gap of .041-.047" for "flex fuel only"; and, AGSF-32N with a gap of .052-.056" for "gasoline fuel only".

I plan to use only gasoline fuel. My thinking is that the AGSF-32N with its higher heat range and wider gap will run better and maybe give slightly better fuel economy on gasoline because it was designed for gasoline. The flex fuel AGSF-22FM1 is designed for E85 which requires a cooler plug to prevent pre-ignition and may run less efficiently on gasoline.

My understanding is that the AP104 Autolite plug is comparable to the Motorcraft AGSF-32N and both are single platinum. The APP104 should be a double platinum version of the AP104. Prior to the Town Car, I had a 1999 Crown Vic which called for and ran better on single platinum plugs.

I would appreciate any informed comments, particularly from anyone who has switched a 4.6L flex fuel engine to the AGSF-32N plug.
 
#5 ·
Actually, I was going to ask the question about E3 plugs. Has anyone tried them yet? I've heard good things about them, but have been skiddish about trying them. My car isn't flex fuel, just a regular 4.6.

John
 
#6 ·
Actually, I was going to ask the question about E3 plugs. Has anyone tried them yet? I've heard good things about them, but have been skiddish about trying them. My car isn't flex fuel, just a regular 4.6.

John
Based on the advice I received from a highly regarded idependent repair shop owner/technician and radio program host, I removed the AGSF-22FM1 flex fuel plugs and installed the AGSF-32N gasoline plugs. He confirmed my thinking that the gasoline plugs will perform better in gasoline than the flex fuel plugs. He also said that spark plugs are a critically important part of the ignition system and that OEM plugs are usually the best choice, aftermarket plugs such as Autolite are OK, but don't bother with the "miracle" plugs like the E3. Personally, I have seen mixed reviews of the E3 and don't think they are worth the risk of damaging your engine.

The car runs smoother and seems to have more "pep" with the AGSF-32N plugs. I will report back later on MPG.
 
#9 ·
The plugs I took out were the factory installed Motorcraft AGSF-22FM1 flex fuel plugs with about 2,000 miles on them. They looked good with clean burning electrodes. However, the AGSF-32N gasoline plugs perform much better and are specified if you plan to use only gasoline up to E10. The AGSF-22FM1 plugs are specified for use of E85 or any mix of E10 and E85. At this point, I don't plan to use any E85.

Also: Since my original post, I have learned that the Motorcraft AGSF-32N plugs are copper/nickel, not single platinum. I am now thinking about when the copper/nickel AGSF-32N plugs wear out at maybe 30,000 miles whether I want to continue using copper/nickel or switch to single platinum. The service life of the copper/nickel is shorter than single platinum, but they may perform better. As I understand it, as you go from copper/nickel to single platinum to double platnum to iridium, the plugs last longer but they are are more difficult to fire and more susceptible to missfire and reduced performance. My LTC does not specify anything other than copper/nickel or single platinum.
 
#10 ·
Single platinum is all you'd need. The earlier Crown Vics had 2 plugs fire at once and one fired electrode to ground and the other the other way around. The platinum was on the ground side on those plugs that fired ground to electrode. Plug gap makes a big difference in mileage. On my 2000, I used single platinum and ran a closer gap than spec.
 
#11 ·
Single platinum is all you'd need. The earlier Crown Vics had 2 plugs fire at once and one fired electrode to ground and the other the other way around. The platinum was on the ground side on those plugs that fired ground to electrode. Plug gap makes a big difference in mileage. On my 2000, I used single platinum and ran a closer gap than spec.
Thanks Bert.

I am expecting that the copper/nickel AGSF-32N that is now in my LTC will last at least 30,000 miles, maybe up to 50,000 miles due to the nickel alloy. After that I am thinking of using a single platinum, but not the factory installed AGSF-22FM1 flex fuel single platinum. A few more questions, if you please:

What would be the Motorcraft single platinum equivalent (32 heat number) of the AGSF-32N? Would that be the AGSF-32PM (SP-493)? What would be the proper gap?

I used the Autolite single platinum AP104 previously in my 1999CV, but would prefer a nickel plated shell. What do you them think about the Autolite AP104?

I don't hear a lot about Champion spark plugs these days, although they were used a lot in older cars. What do you think about the Champion 3401 single platinum?

Is there any other brand of single platinum 32 heat range plug that works well in a COP panther?

Some of these plugs are finewire and when you see them in an auto parts store listing often have a closer recommended gap of .040 to .044" instead of .052 to .056". Is a closer gap typical of finewire technology, or lower heat range?

Am I correct in thinking that I should use a 32 heat number plug for my easy-goes-it driving style and E10 gasoline?

Do you know of a heat range conversion/comparison chart that includes Motorcraft, Autolite, Champion, Denso and NGK?
 
#12 ·
We've used the AP104 in our fleet and have good luck with them. We set them at .045. The Champion plugs are something we would NEVER use. Too much trouble with them. Motorcraft or Autolite is all we use in our fleet. In the older Crown Vics from 97 and older, we used the dual platinum because of the way they fire.
 
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