GEN 2 Which plug should I go with Sp 550 or Sp578?

[Wender85]

I was tracking .28 but now im not sure it you find out let me know.

 

[sixshooter_45]

Following

 

[Grayson]

I have a set of these (-1 because i dropped one) when I say they are cold natured, I couldn't get the vehicle to crank even with adjusting the gap. This was on a 3.0 Ecoboost which is a nightmare compared the the ease of a 3.5L IMO

 

[K-Doob]

SP542s are the best OEM plug, especially if running a tune. Unfortunately they can be difficult to find these days. Last set I had to piece together from local auto stores and ebay sellers.

 

[digscruze]

I believe the 542’s were rebranded and are now under a new part number M-12405-35T. There’s a previous thread about that.

Otherwise they’re pretty common to find. SPD Performance and MPT are some of the few that carry them. At the time of this writing, they’re running a sale on them now for under $50 for the set of 6.

Ford Performance 2010-2019 3.5L Ecoboost Cold Spark Plug Set M-12405-35T

www.morepowertuning.com

 

[costnsg]

I am planning to change plugs on my 2017 Raptor with 95,000 miles. Manual indicates change after 100,000, so I'm about there. Unfortunately, the proper plug is a little confusing. My truck is stock, btw.

My manual supplement shows proper plug is SP-534. Online searching for ford parts and the local Ford dealer says SP594. My online searchs indicate the SP594 is a replacement for SP542 and SP578. So, is SP594 the proper plug? I haven't found SP594 mentioned on this forum.

Online and in this forum I have found advice to use 133 in-lbs to torque the plugs. I didn't find a torque value for the bolt holding the coil.

Anti-sieze is another variable, but after reading lots of back and forth about whether to use it, I am leaning toward not using. I expect the torque values are based on no lube. Lubed fasteners will definitely develop more bolt stress with the same torque versus dry, so I expect the same principles apply to a spark plug (probably screws into head a little further with lube vs without).

So, looking for confirmation to use SP594 plugs torqued to 133 in-lbs without anti-sieze. I'd also be interested in torque values for the small coil fasteners if someone has that, otherwise I'll try to be careful with them (not too tight).

 

[element217]

Ford Performance M-12405-35T Spark Plugs (RAPTOR /F150 ONLY!) | GooseTuned

**THESE ARE NOT PRE-GAPPED!! They will need to be gapped to .026-0.028***** For use on 2017-2022 3.5 Raptor/F150 and 2018-2020 2.7 F150 only**Spark Plugs, Iridium Tip, Tapered Seat, 14mm Thread, 0.750 in. Reach, Projected Insulator, Resistor, Ford, Set of 6 plugs NO RETURNS on an opened set of...

www.goosetuned.com

 

[sobiloff]

So, looking for confirmation to use SP594 plugs torqued to 133 in-lbs without anti-sieze. I'd also be interested in torque values for the small coil fasteners if someone has that, otherwise I'll try to be careful with them (not too tight).

I'm installing the SP-594 plugs on my '17 and can confirm the shop manual specifies 133 lb in and makes no mention of anti-seize. The coil-on-plug retainers (bolts) are tightened in two stages: first to 62 lb in, and then an additional 50°.

 

[EagleRaptor]

I replaced the factory plugs at 70k with sp550, the engine ran much smoother. There are a lot of different part numbers that seem to change on a regular basis for this motors spark plugs.

I think they call for sp594 now, but I have had good luck with sp550.

 

[brianh87]

I used the 594's on my stock Raptor. That's what the old plugs superseded to according to the research I did. And 133 in-lbs is straight from the service manual.