1/26/2010: I rode in a repairman's F150 (late model, year unknown) last week. He told me that other owners are paying $500 to $1,000 dollars to have plugs changed out. I was shocked. I have a 2006 F150 with 65,000 miles on it. I have considered changing them out now thinking it might cost less in the long run. A couple of mechanics I talked to did not recommend the early change because of the expense. I began regretting selling my 1992 Chevy.
The computers on these trucks adjust the spark as needed. Why not let the plugs go 200,000 or 300,000 miles?

 

I second that factory plugs are ! As far as what I put in, I went with a set of NGK Racing plugs, a 9 to be exact. This way with "cooler" plugs I can add timing

 

I changed mine at 40,000 and it was more for piece of mind later down the road when I get some real miles on it. Ford recommends that they be changed at 60k instead of 100k now, but what do they know, right? I'm not an engineer, thats why I buy the watch instead of build it, but we are talking about a big piece of a man's paycheck if left unchecked. Common sense would tell me to have a little "insurance" in my $35,000 investment and try get ahead of the problem. All in all, get your plugs changed early, between 50 and 60k.

And 3wV, you don't need to drink, type and read an enginnering book at the same time. It makes for dull conversation.

 

67,000 miles plugs were fouling and 5 broke off. $375 for plugs and coil boots and $650 for labor. On. top of that. Cats were bad (under warranty) bad throttle body and Mass air flow sensor. So i went ahead and put BBK TB and Jet MAF and threw a Banks CAI while I was at it. Dont know what happened but all this took place in about a month. Very happy with it now though!

 

I just bought my truck and it has almost 60k miles on it. The spark plugs were one of the things I wanted to change for a multitude of reasons. A.) to get a head of the power curve. B.) Better gas mileage C.) Possibly a better spark/plug. Would there be any suggestions as to which to go with. I was thinking Bosch platinum as they have a pretty hefty reputation but I am willing to consider others that have been tested by other folks.
2006 XLT 4X4

 

Personally I would stay away from Bosch plugs!!

 

[quote=dfusilier;378383]67,000 miles plugs were fouling and 5 broke off. $375 for plugs and coil boots and $650 for labor. On. top of that. Cats were bad (under warranty) bad throttle body and Mass air flow sensor. So i went ahead and put BBK TB and Jet MAF and threw a Banks CAI while I was at it. Dont know what happened but all this took place in about a month. Very happy with it now though![/quote



Did you stay with a stock size TB or go larger? If larger did you notice a difference?

 

What types would you suggest that might help me achieve my objectives?

 

Bosch plugs come with a hefty reputation of being crap. I could crap into a mold of a spark plug and you would have better luck with that than a Bosch plug. Spark plugs aren't magical. A stock engine does just fine with a stock plug. The only time you need to tinker with plug heat range, gap etc is when you do some sort of internal mod, forced induction or nitrous. Spark plugs will work as long as the coil firing it can supply enough voltage to jump the spark plug gap. The wider the gap, the higher the voltage which makes the coil work harder and get hotter. Wait too long and you can burn a coil out. Not that the COP on these trucks are that tough anyway. There is no way to accurately determine how wide the gap will be at any given time. I replaced my plugs at about 52k and they were easily .080". The engine ran fine before with the exception of a cold full throttle misfire. Since changing the plugs, the misfire is gone. I would assume having bought the truck used, the truck idled a lot.

 

"Wait too long and you can burn a coil out. Not that the COP on these trucks are that tough anyway."

I asked about COPs a while back and was told not to worry about the stock units?? I was looking at the Granatelli MPG ignition wire set, so can I assume that they have beefier components? How many people have non stock COPs?
I am running an '05 STX 4.6L no mods.