Tank
9/11 - Never Forget
- Joined
- Feb 19, 2016
- Posts
- 2,914
- Reaction score
- 1,655
- Location
- New England
- First Name
- Jim
- Vehicle(s)
- G0853
Just make sure you swap out the MichelinsHere’s a pic of oil recommendations from my 2020 GT350 supplement![]()

Just make sure you swap out the MichelinsHere’s a pic of oil recommendations from my 2020 GT350 supplement![]()
The owners supplement has always stated that 5w50 API certified equivalent oils are acceptable.Wow, thanks for posting this. Big change! I assume this recommendation is backwards compatible through all years?
Also, look right above that regarding the 5w50 oil ... says oil needs to meet WSS-M2C931-C OR API SN requirements. That opens up oils not on the current approved list and is BIG!
Not really, attached is screenshot from my 2019 Owner's Manual, which is VERY different than what is written in the 2020 Owner's Manual.The owners supplement has always stated that 5w50 API certified equivalent oils are acceptable.
"Your engine has been designed to use engine oil that meets our specification or an equivalent engine oil of the recommended viscosity grade that displays the API Certification Mark for gasoline engines."
The way I read it is that the WSS-M2C931-C is still the recommended oil, if you absolutely are unable to use it then any 5w50 API SN certified oil will work. Like in an instance that you are down a quart in the middle of nowhere and it is your only option.
Yep..already looking at options to swap in the Spring when she comes out of hibernation. Tires were like hockey pucks when I took her around the block on Saturday and temps were in low 40s.Just make sure you swap out the Michelins![]()
2016 said this--nothing about API:The owners supplement has always stated that 5w50 API certified equivalent oils are acceptable.
"Your engine has been designed to use engine oil that meets our specification or an equivalent engine oil of the recommended viscosity grade that displays the API Certification Mark for gasoline engines."
The way I read it is that the WSS-M2C931-C is still the recommended oil, if you absolutely are unable to use it then any 5w50 API SN certified oil will work. Like in an instance that you are down a quart in the middle of nowhere and it is your only option.
You're right, there is an interesting new statement in the 2020 GT350 Supplement...that directly goes against people using any ol' 5w50 oil.Not really, attached is screenshot from my 2019 Owner's Manual, which is VERY different than what is written in the 2020 Owner's Manual.
![]()
I wouldn't and I think your missing the point of this thread. Prior to 2020, the only oil Ford said to use were those that met their WSS-M2C931-C specification. With 2020 they are now saying oils to use are those that meet their 'C' specification or those that meet API SN requirements. As an example, prior to 2020 Ford would not recommend using say Mobil 1 5w50 since it does not meet their 'C' spec but since the M1 oil does meet API SN requirements, it is approved in 2020. Again, a big change.You're right, there is an interesting new statement in the 2020 GT350 Supplement...that directly goes against people using any ol' 5w50 oil.
"Oil must meet specification WSS-M2C931-C or use SAE 5W-50 oil that meet API SN requirements."
The only reason the "or use SAE 5W-50 oil that meet API SN requirements" exists in there is because Ford cannot legally tell you what oil brand to use. So long as it is the correct viscosity and meets API SN requirements, you are protected under the Magnuson Moss Warranty Act.
So why would you use an oil that the engine was not specifically designed to use?
2019 GT350 Supplement:I wouldn't and I think your missing the point of this thread. Prior to 2020, the only oil Ford said to use were those that met their WSS-M2C931-C specification. With 2020 they are now saying oils to use are those that meet their 'C' specification or those that meet API SN requirements. As an example, prior to 2020 Ford would not recommend using say Mobil 1 5w50 since it does not meet their 'C' spec but since the M1 oil does meet API SN requirements, it is approved in 2020. Again, a big change.
is because 931-C is equivalent to API SN and they "forgot" to mention that in the previous edition. 931-B corresponds to API SM.oil must meet specification WSS-M2C931-C. The only reason "or use SAE 5W-50 oil that meet API SN requirements"
I spent the $30. It was worth it to me. There are differences between 931C and API SN in high temperature deposit formation and in phosphorus content. Phos is the biggie - API SN contains 25% more phosphorus than 931C, which is not good for your cats if you're consuming oil. For instance, I'll run API SN during the winter when the car goes for a drive every couple of weeks, but I want 931C when I'm using 2 quarts a month going to track days. I also bought 931D, which is the API SN Plus version of 931 for FI engines. It adds the extra LSPI tests for SN Plus and reduces or removes some of the other differences, although it's still a lower-phos formulation.is because 931-C is equivalent to API SN and they "forgot" to mention that in the previous edition. 931-B corresponds to API SM.
If Ford had any sense they would publish the details of the additive package. At least the broad specs are:
https://www.fcsdchemicalsandlubricants.com/main/additionalinfo/Product Data Sheet 5W50 Full Synthetic.pdf. I don't feel like paying $30 to read https://standards.globalspec.com/std/13067150/FORD WSS-M2C931-C to see what it brings to the discussion.
Phosphorous is a good anti-wear ingredient in oil. I would rather have to replace catalytic converters in some distant future instead of having to replace the engine.I spent the $30. It was worth it to me. There are differences between 931C and API SN in high temperature deposit formation and in phosphorus content. Phos is the biggie - API SN contains 25% more phosphorus than 931C, which is not good for your cats if you're consuming oil. For instance, I'll run API SN during the winter when the car goes for a drive every couple of weeks, but I want 931C when I'm using 2 quarts a month going to track days. I also bought 931D, which is the API SN Plus version of 931 for FI engines. It adds the extra LSPI tests for SN Plus and reduces or removes some of the other differences, although it's still a lower-phos formulation.
I'm not sure that there's a discernible performance difference between the 931C/D low phos (800 ppm) formulation and the regular API SN high viscosity 1000 ppm formulation. API SN for lower viscosities up to xw30 limits phos at 800, so all Ford did was adopt the lower viscosity phos level for their 5w50 higher viscosity oil. Engines running xw20 and xw30 API SN oils aren't failing all over the place, so whatever formulators did to compensate for lower phos seems to have worked. I suspect it costs formulators money they don't need to spend to reduce the phos in xw40 and xw50 oils, so, with only a few exceptions, they haven't bothered.Phosphorous is a good anti-wear ingredient in oil. I would rather have to replace catalytic converters in some distant future instead of having to replace the engine.