Oils, the full synthetic stuff, different Ford WSS

[CajunMick]

WSS-M2C961-A1 vs. WSS-M2C971-A1

Can anyone explain difference between the 961 and 971 in WSS #? I seem to recall reading that 971 full synthetic maybe supersede the 961 specs. Not able to find info, again. My 5W-30 oil of choice is full synthetic and says ford approved WSS-M2C971-A1.

And I know the manual for my 2023 says the 961 stuff.

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[CajunMick]

I may have found some information on this 971 oil specs. Looks to be a newer standard of motor oils. The 961, GF-6 appears to be 2020 specs. Then newer improved 971, GF-7A is a March 2025 specs, supersedes 961. Oil containers, bottles with the new GF-7A, WSS-M2C971-1A markings just hitting the shelf. This explains why my recently purchased new bottles of Quaker State 5W-30 full synthetic has this nomenclature.

This copied from another manufacturer information.

“Designed to inhibit incidents of LSPI (low-speed pre-ignition), a combustion event that can cause premature wear or catastrophic failure.

SAE 5W-20 - API SQ • GF-7A • CHRYSLER MS-6395 • FORD WSS-M2C970-A1

SAE 5W-30 - API SQ • GF-7A • CHRYSLER MS-6395 • FORD WSS-M2C971-A1

 

[Allen King Jr]

Ford only makes one full synthetic oil in 5w30

XO-5W30-Q1FS is the part number

 

[CajunMick]

Additional details on the 971, GF-7A oil, specs. This is Quaker State, a oil packaging company owned by by Shell Oil, which also own Pennzoil. I brought 6 qts, had truck oil change today.

i doubt nor seen any Motorcraft (c/o Phillips 66) oil with this improved lube specs. ??

https://www.shell-livedocs.com/data/published/en-US/60c77c7a-7b33-4eb8-9d12-3f94364fd983.pdf

Supposing this lube intentions are for low speed detonation by direct injection, turbo boost, higher temperature, better lubrication of chains and low slug effect.

 

[CajunMick]

Ford only makes one full synthetic oil in 5w30

XO-5W30-Q1FS is the part number

Ford supplies it, does not make it, Phillip/Conoco does.

 

[CajunMick]

Got confirmation from Shell/Quaker State technical staff. The QS 5w-30 lube oil oil is acceptable for my 2023 Maverick 2.0 EB engine.

“Case No: 00725959
Enquiry: FW: Full synthetic, Ford WSS-M2C971-A1 vs WSS-M2C961-A1
Hello,

Ford WSS-M2C971-A1 is an updated specification and replaces/supersedes WSS-M2C961-A1.

For your vehicle which requires the latter, please use Quaker State Full Synthetic SAE 5W-30 Motor Oil with full confidence.


Hope this clarifies.”

Reason why I switch to Quaker State is due to Motorcraft oil, blended or full synthetic, exhibiting low viscosity numbers. QS specs reads viscosity at 10, higher than the Motorcraft. I plan to put some miles on the QS oil, pull sample and see what numbers will be.

 

[CajunMick]

The local Ford Quicklane change the oil, did that “The Works” stuff. Told service writer I want to supply the oil, in this case the Quaker State full syn. Told him the oil meets For WSS-M2C971-A1 specs. He not listened well cause he wrote up ticket as customer supplied own oil, and “no warranty“. Obviously not understanding or lazy, not realizing the Quaker State fully qualifies, and prob better than the bulk oil they have, use.

 

[L O B O T]

(talking ecoboost)

I would just keep your 'oil purchase' receipts stapled to your ford dealer receipt for any future reference and sleep better knowing the 71-A1 supersedes 61-A1.

 

[Cancunbadlands]

Performance Standards: The 961 specification was introduced to align with ILSAC GF-6, which focused heavily on preventing Low-Speed Pre-Ignition (LSPI) in modern turbocharged engines (EcoBoost). The 971 specification aligns with the newer ILSAC GF-7 standards (introduced around 2024–2025), which demand even tighter controls on oil breakdown and engine deposits.
Interchangeability: If your Ford vehicle (like a 2021+ F-150 or Maverick) lists WSS-M2C961-A1 in the owner's manual, you will likely see the newer bottles on store shelves marked with WSS-M2C971-A1. Ford and major oil manufacturers (like Quaker State and Mobil 1) confirm that the 971 spec is the intended replacement for 961.

 

[CajunMick]

(talking ecoboost)

I would just keep your 'oil purchase' receipts stapled to your ford dealer receipt for any future reference and sleep better knowing the 71-A1 supersedes 61-A1.

Yep. What I’m doing.

 

[Cherokee]

I’ll never get that deep into it.
way I see it, running a shitty full synthetic is worlds above roach oil. And I’ve taken motors well beyond 350,000 miles with ROACH OIL AND 10,000 mile service intervals.
Too many to dismiss for me.
I did look at Motorcraft’s ONE synthetic they sell. It’s plenty, ‘Good Enough’ for me.
I don’t do additives for two reasons.

1. Put in 12 ounces of an additive your putting in 12 ounces less oil and that means less of the factory oils long studied proven performance additive package.

2. There ain’t no such thing as a mechanic in a can.

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