Plugs- Autolite AP103?

[Reddleman]

Ordered some plugs for the new-to-me Ranger and got the Autolite AP103.

While I waiting for my Rockauto order, I saw that they actually recommend double platinums and the AP103 is single (APP103 is double).

Is this a problem, or should I spend the extra $35 to go out and get a set of double-platinums?

 

[adsm08]

It will run ok with the single platinums, but you will wear half of them out about twice as fast.

The spark travels backwards across half the engine (I do not know which half) and so single platinum plugs used on that side will wear out faster because the spark is moving from the soft metal to the hard metal. On the side that is going from hard to soft you won't lose as much material, and won't wear them out that fast.

The reason double plats are recommended is so you don't have to worry about which way your spark goes, or making sure you have the right plugs in the right holes if you managed to get the "reverse platinum" ones that would have been used at the factory.

 

[delaware74b]

I made the same mistake a couple years ago. I believe it will the the driver's side that will wear the plugs before the passenger side. I use the APP103, although I might look into the iridium (XP103) on the next change-out.

 

[8thTon]

I looked at the plugs that were in my 3.0, and they are Autolite Iridium XP104. They've been there a little while based on the crap on the threads, and they are holding up quite well. The Iridium center electrode is a benefit with the wasted spark ignition - I may put them in my Cougar.

Note that these should have been XP103 plugs. The XP104s had a faint white deposit on the outside of the ground electrode which may have been due to the slightly hotter heat range.