I installed single platinum Bosch plugs in my 3L 2V engine (Vulcan). Ran great for 60,000 kms. Then started a misfire on plug #6 (drivers side). When I replaced the Bosch plugs, an inspection revealed that the centre electrodes were burnt on the driver bank of plugs (X3). The other bank (passenger side) looked fine, this agrees with the reverse polarity theory. Moral of the story .... use the double platinums (Motorcraft AGSF32FM), unless you enjoy plug replacement for the hell of it.
BTW the engine runs stronger & starts better with the Motorcraft plugs, the same engine ran 237,500kms on the original set!!!
Aeroman.

 

I haven't read all the threads posted here, but I installed Bosch Platinum Plus 4 in both my Ranger and MH. What a power difference. Little better on fuel mileage also. Here's a link to the Bosch site.

Bosch Platinum+4 Spark Plugs, Platinum Plus Four Spark Plugs, Four Electrode Spark Plugs

Back in my drag racing days, we used to install new plugs on race day with the ground contact filed back to expose 1/2 of the electrode. This allowed the "fire" to be exposed directly in to the combustion chamber. It didn't have to travel arould the ground tip. At least that was the theory our pea brains used. Must have been something to it as manufacturers using the 2 or 4 ground tabs are going to it.

 

i put bosch 4 electrode platinum in my last 4ltre and notice an immediate and obvious
power increase, i think because the elrctrode was not shielding the spark

 

I put Autolite XP104 Iridium plugs in my 3.0L with Motorcraft Wires and I am very impressed. Noticeable performance gains over the Autolite platinums it had in it (just bought it so I'm not sure when they were last done, has 120K miles). Perform especially well at high RPM where my old plugs just couldn't keep up. They are very cost effective at just 2.66 per plug with rebate via Rockauto.com and $35 for the Motorcraft wireset.

 

my bro in law used to race mod u 2 stoke boats 350 hp, 1100 lbs with driver
v6 merc engine, the plugs had no electrode, bottom of plug looked like 2 concentric
circles. that suggested to me that unshrouding the spark may provide some power in a 4 sroke motor 2

 

Mercury use "thunderbolt' ignition, good way to stop 2 stroke fouling plugs at low RPM"S. 4 stroke on unleaded gas is a different animal. New plugs of almost any kind will likely show a power increase over old worn /overgapped plugs!

 

I have motorcraft platinum AGSF 32FM in my '96 Ranger 3.0. It doesn't say double platinum. However, the guy at advanced auto said this is the required plug. Is this the correct plug?

And when I got the plugs, they were gapped to .055 in. so I regapped it to .045 in. according to my Haynes manual which says .042-.046. Now, I don't have a label under my hood for some reason so I don't know what the gap is suppose to be. So I am relying on my Haynes manual. My next question is, what should I gap these plugs at if they are the correct plugs?

 

That is the correct plug, .045" is the gap I set mine to as stated in the Haynes manual. After 18 months all is well. The engine will fire adequately with a much larger gap (since it will wear bigger over time).So for maximum longevity start at the .042" gap, after a while you will be at .045 & eventually to .075" or bigger! Mine came out at .100 when I eventually replaced them!

 

Just put new motorcraft plugs in my sons 05 Taurus that his wife drives back and forth every day to work. Car has 176k miles and never had plugs changed. Took 2 of us to replace the 3 on back side(fwd) of the 3.0 v6. It started missing and running bad couple of days ago and I didn't realize how many miles she had on it. Took three hrs to replace rear plugs and wires and about 15 min for front 3. Center electrode was gone and worst plug I've seen in a while. Couldn't believe it still ran at all. It's purring like a kitten again.

 

I've been experiencing spark knock in my '02 B3000 "U" VIN, for a good while now, under heavy load. I went from 87 to 89 octane gasoline and that has seemed to help calm it down some. However, I've always suspected ethanol is the gremlin at work. From Bob's statement, and what others have said, I'm wondering if the recomended AWSF32PP is too hot, in my engine, with the 10% ethanol we find at most pumps these days? Or, maybe it is just the driver's side plugs, with the polarity difference? Anyway, I'm trying to decide if I should go with a colder plug? What about just the plugs on the "hotter" side? Or, am I asking for trouble?

I pulled my #1 plug and, after 68,000 miles, it didn't seem excessively worn, nor fouled. Although, to my eyeball, the gap looked too large. I haven't pulled a plug from the other side of the engine to see it has suffered more. Would too much gap contribute to spark knock?

 

I just put new Champion platinum plugs in my 92 Ranger about three weeks ago and I have a misfire somewhere and reading this forum I find out that Champion and a lot of the other plugs cause misfires so I just went to Autolite double platinum for my 4.0 engine today and still had the problem so I had bought a new set of premium ignition wires (lifetime I believe) from Orilley Auto so I installed them also but I still have the misfire. It's especially bad upon reaching about 42 to 55 MPH. I really rattles then, so you have to back off the accelerator. Anybody think they might have a clue what's next ? Thanks Hank

 

I've read thru this thread, and it has loads of good info, thanks guys! But I was wondering if this same info applies to the dual plug four cyl???

 

Like I said Tuesday I believe, my misfire was a bad fuel injector on no. 5 cylinder but being that is replaced now, it runs just fine. capthank

 

What about irridium? Anyone have any advice on them?

 

If the truck has a coil pack, it has EDIS, correct?

Paul