Ford V-10 sparkplugs (SP 479 or AP 103)

Either is fine. My understanding is Autolite is the MFG of that particular Motorcraft plug. My local dealer even stock the Autolites instead.

I used the Autolites when I did my plugs at 50k miles. I now have 94k and am going on a 2 week 3500 mile trip. I'll probably go with Motorcraft plugs this time around. I'm also doing all new boots too.

From Wikipedia

3-valve 5.4 L and 6.8 L engines built before 10/9/07 and 3-valve 4.6 Ls built before 11/30/07 found in many 2004–2008 Ford, Lincoln, and Mercury vehicles have an issue with difficult-to-remove spark plugs, which can cause part of the spark plug to become seized in the cylinder head. The source of the problem is a unique plug design that uses a 2-piece shell, which often separates, leaving the lower portion of the spark plug stuck deep in the engine's cylinder head. The 2-piece OE spark plug design is intrinsically flawed, thus making it susceptible to this problem. Ford acknowledges this issue in TSB 08-7-6 as well as earlier TSBs. Ford's TSB does not state that this issue is caused by owner neglect. The TSB provides a special procedure for spark plug removal on these engines.

I'm not sure it is "official" from Ford, but most mechanics just use a 3/8" impact on the plugs in a hot engine.

dodge guy wrote:
I used the Autolites when I did my plugs at 50k miles. I now have 94k and am going on a 2 week 3500 mile trip. I'll probably go with Motorcraft plugs this time around. I'm also doing all new boots too.

My understanding is the Autolite is a double platinum plug and the Motorcraft is a platinum plug. The Autolite is more expensive then the Motorcraft. Will replace my coils as well. Since I don't know if plugs have been changed I'll let my mechanic do it. Usually I do most my own maintenance.

carringb wrote:
Either is fine. My understanding is Autolite is the MFG of that particular Motorcraft plug. My local dealer even stock the Autolites instead.

What do you use?

I've used both. I'm now running AutoLite iridium plugs. The platinum only last me ~60,000 and double still only about ~75,000 miles. This is because the tune I'm running which is pretty aggressive. The iridium let me make it all the way to 100,000 miles again. I don't feel they are necessary for a stock tune.

Thanks for the replies, I bought the Autolite APP103.

Beware those coils add up quick for ten. If your mechanic has Mode 6 on his scan tool he can check to see if any have misfires.

On the coils. Just do what I do. I carry to extras with me. I won't install any new coils until they fail just because of the price alone. $500-$600 for 10! More or less depending on where you get them.

$500 is cheap insurance, when you're 800 miles from home.
I was a Ford tech for 25 years. The last place I would want to do coils is ,on the side of the road.