Motorcraft Platinum Sparkplugs

[Snagglefoot]

In the attached photo I have a thirteen year old Motorcraft Platinum Sparkplug with a "Standard" Platinum electrode. It came off a 2005 Taurus with 70,000 miles. I believe the plugs are original. To the left is what the Ford dealer says is the correct replacement plug. It has a "Fine wire" Platinum electrode. Does anyone recall when Motorcraft went to the "Fine wire electrode? At first when I looked at the original plug I thought OMG , the tip got totally eroded off, but now I'm thinking it never had the "fine wire " tip in the first place.

 

[StevieC]

Not sure when but Rock Auto also lists the Fine Wire

MOTORCRAFT SP433 {#AGSF32WM, AGSF32WMF4} Finewire Platinum

https://www.rockauto.com/en/moreinfo.php?pk=1017153&cc=1430709&jsn=446
Quote
The Finewire Platinum spark plug was designed to improve electrode wear beyond the capability of the Single Platinum spark plug. The quantity of platinum is 2 to 3 times greater than the Single Platinum plug and its thin cylindrical shape serve to reduce the required firing voltage. This results in diminished erosion of the platinum and robustness against fouling.

 

[xxch4osxx]

That's a big gap on the old plug. Looks like it might have had the fine wire in it.

 

[oldhp]

Plug part numbers the same?

 

[tig1]

The new one looks like an iridium plug.

 

[Snagglefoot]

Originally Posted by oldhp
Plug part numbers the same?


The original plug is a AGSP 32 PM. The new plug that Ford said to use is a AGSF 32 FM.

A = 14 mm
G = 0.75 " seat
S = Suppressor
P = 5/8" Hex

3 = level 3 heat range
2 = Extended Power tip
P = Standard Platinum Electrode
M = Nickel Plated Shell

The first F = Conical seat ( they now describe a conical seat rather than describing the 5/8 inch hex )

The 2nd F is Finewire Platinum Center Electrode

The new plug is also called the SP432. There is a version that is one colder,
The AGSF 22 FM. That one is called the SP 500. Both are listed at Rock Auto.

 

[Snagglefoot]

Originally Posted by tig1
The new one looks like an iridium plug.


Yes, but the Motorcraft Finewire Platinum Center Electrode design now looks similar to an Iridium. I believe the second F gets replaced by a W for the Iridium plug.

 

[Snagglefoot]

Originally Posted by xxch4osxx
That's a big gap on the old plug. Looks like it might have had the fine wire in it.


That's what I was thinking at first. The last P on the plug description is supposed to designate a "Standard Platinum Electrode". So that's the question. What did the tip look like back in 2005? Was it a skinny looking wire or did the entire "fat" electrode get worn down.

 

[Whipcitywrencher]

Odds are it was a fat tip,
Autolite makes motorcraft spark plugs, and they came out with there first autolite finewire plugs in 2005, one would think the motorcraft finewire plugs were made sometime after.

Check out page 3 in this autolite manual
http://www.autolite.com/media/14882/technical_training_manual.pdf