So in my chart, they should be good from stock to 6+ psi?
That seems like it's not a stock plug or it's a very good all around plug.

 

So you're saying the 12FM1's are Iridium and came stock in my 2000 L a year and a half before anyone heard of Iridium plugs on the boards.

 

If there listed as stock L plugs, I would think they only come on the 03/04 L's if any at all. It's probably just an upgrade plug for a stock L and never actually came installed on the vehicle.

Anybody else know more info on these plugs?

 

the 12fm1 came stock in all L's and are iridium. Ford knew what they were doing when they spec'd that plug.

I have a set of 12fm1's i pulled from my truck (03)

 

This is the info that I found at www.motorcraft.com.


Part No.: AGSF12FM1
Manufacturer: MOTCR BASE
Part Type: SPARK PLUG, PREMIUM/PLATINUM
Total No. of Vehicles: 7
FORD (7)
PICKUP F150 HARLEYDAVDSON (2)
2002 5.4L 330cid Fuel Injected V8 Supercharged Vin:R
2003 5.4L 330cid Fuel Injected V8 Supercharged Vin:R

PICKUP F150 LIGHTNING (5)
1999 5.4L 330cid Fuel Injected V8 Supercharged Vin:3
2000 5.4L 330cid Fuel Injected V8 Supercharged Vin:3
2001 5.4L 330cid Fuel Injected V8 Supercharged Vin:3
2002 5.4L 330cid Fuel Injected V8 Supercharged Vin:3
2003 5.4L 330cid Fuel Injected V8 Supercharged Vin:3

 

FINALLY! Someone who I can agree with on the proper plug heat range. Yes a TR6 is equivalent to the stock heat range. I would like to point out that the TR5 and TR55 are the same plug(heat range) with different gap settings. The TR55 is for larger gap settings, like an n/a F150. It makes absolutely no sense to run the same heat range plug in my L that I would run in my n/a F150. I would not run a TR5 in my L. NGK now makes iridium plugs as cold as a TR8IX. A good choice over the expensive Denso plugs.

 

Finally someone who knows what they are talking about!

If you go to the NGK site they cross reference the tr6 as equivalent to stock heat range, I don't know why you all find that so hard to believe. and YES the FM1 is iridium. Compare the construction and shape of the electrode to a denso, it's fine tipped form is VERY similar.

 

Yep the stock plugs are or at least have iridium. I was under the impression they are an iridium platinum combo? Wether that means the electrode is iridium and the ground electrode contains platinum, I'm not sure.

 

Ok,
1.) TR5's/TR55's are now out
2.) BR7's should be installed in the place of TR6's
3) and Ford has updgraded plugs on 03 and up L.

The Motorcraft stock replacement Iridium plugs for our L's should be the same heat range, right? And if they are colder, why are they stock replacements?


WHY DO VENDORS TELL US THE TR6'S ARE 1 HEAT RANGE COLDER THAN STOCK.
An explanation from a vendor would be helpful.

 

So what is the part # for the BR7's? My store only has the TR6's listed in their computer...

 

It's BR7EF ... AutoZone, Advance Auto Parts, etc, can reference that model and find their own part #. I know for a FACT that AutoZone carries or can get the BR7EF. I run them.

 

Autozone couldnt get the BR7EF for me but Advance/Discount was able to. Whoever is the NGK distributor may vary by region.

Part number is BR7EF and stock code was 3346 when I ordered.

3346 is the internal number NGK uses or something, they were able to find it immediately using that.

 

So 3346 is the NGK# on the box. Thanks!

 

The iridium plugs are on ALL lightnings from 99-up

Vendors probably say that because the TR6 seems more resistant to detonation in that the plug itself remains intact, much like a denso iridium plug in the same heat range as the br7 is just as cold, however more fragile and will not survive light detonation/knock.

 

The stock plugs are not Iridium.

Part No.: AGSF12FM1
Manufacturer: MOTCR BASE
Part Type: SPARK PLUG, PREMIUM/PLATINUM