When did Ford change the recommended engine oil for the GT?

[ice445]

I wonder if Ford plans to issue a TSB about this to fill all Gen 3 motors with 5W30, or if its just a change for 2021 only. If it's the latter I will find that very strange. Lots of cars will get filled with 5W20 out of habit.

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[EFI]

But then the 2021 manual also says this on page 283 so there's a conflict or typo that doesn't match the 5w30 that is clearly stated later in the manual

Is this in your personal manual eg. from a Candian market car? It may be different for the colder climate up there than the USDM one.

 

[Vlad Soare]

I'm looking at the online manuals on the Ford Romania web site.
If I search for a 2020 Mustang (i.e. mine), it says WSS-M2C948-B or 5W-20. This is consistent with my printed manual, as well as my oil filler cap.
If I search for a 2021 Mustang, it says WSS-M2C950-A and no SAE rating.

A quick Google search for the WSS-M2C950-A specification seems to suggest that it's 0W-30.

They say the second manual applies to cars produced after September 14th 2020. The first one is for cars produced after July 15th 2019.

 

[Qcman17]

Is this in your personal manual eg. from a Candian market car? It may be different for the colder climate up there than the USDM one.

No I just searched to see what the 2021 manual specified. We have the same oil requirements as US cars my 2019 has 5w20 on the fill cap. I wish the OP would report back on his oil cap because there are some discrepancies on Ford's end for sure.

 

[Qcman17]

I'm looking at the online manuals on the Ford Romania web site.
If I search for a 2020 Mustang (i.e. mine), it says WSS-M2C948-B or 5W-20. This is consistent with my printed manual, as well as my oil filler cap.
If I search for a 2021 Mustang, it says WSS-M2C950-A and no SAE rating.

A quick Google search for the WSS-M2C950-A specification seems to suggest that it's 0W-30.

They say the second manual applies to cars produced after September 14th 2020. The first one is for cars produced after July 15th 2019.

Yes I saw the A designation as well and I knew mine was a B. Thx for looking that one up!

 

[GreenS550]

I have been using synthetic 5W30 in my Mustangs for years. 5W50 synthetic if supercharged (Whipple and Roush recommend this). Makes sense.

 

[Strokerswild]

I've always used 5W-30 in my '15, mainly because everything else in the fleet calls for it. And I don't believe in the potential tradeoff of mileage over protection.

 

[Derkluge]

As EFI asked, "What does your oil cap say?".

The oil cap in the '21 GT (at least mine) says 5W-30, clear as day.

I personally think Ford should tell its '18-'20 GT owners if it has found that 5W-30 is all-things-considered better for their engines than 5W-20.

 

[jimbabwe]

I've always used 5W-30 in my '15, mainly because everything else in the fleet calls for it. And I don't believe in the potential tradeoff of mileage over protection.

Is there any risk of Ford denying engine warranty claims if something (major) happened and you used 5W-30 vs 5W-20, since our manuals don't specifically call for 5W-30 anywhere?

 

[Strokerswild]

Is there any risk of Ford denying engine warranty claims if something (major) happened and you used 5W-30 vs 5W-20, since our manuals don't specifically call for 5W-30 anywhere?

No idea.

 

[EFI]

Is there any risk of Ford denying engine warranty claims if something (major) happened and you used 5W-30 vs 5W-20, since our manuals don't specifically call for 5W-30 anywhere?

Can't say never, but it would be pretty darn hard for Ford or anyone else to tell what oil and viscosity was used especially with the minor difference between 5w20 and 5w30.

Now if you used a 10w60 or the complete wrong oil not meant for gasoline engines, they'll be able to tell. But can't imagine Ford would be able to distinguish between 5w20 and 5w30 oil after 5000 miles.

 

[Qcman17]

The oil cap in the '21 GT (at least mine) says 5W-30, clear as day.

I personally think Ford should tell its '18-'20 GT owners if it has found that 5W-30 is all-things-considered better for their engines than 5W-20.

Thanks for confirming that. I would love to know what their reasoning was but they will likely never divulge it.

 

[Vlad Soare]

Now the question is, what should we use in a 2020 engine?
The fact that the 2020 manual hasn't been updated, but they chose instead to publish a different one for 2021, seems to suggest that the new recommendation applies exclusively to 2021 engines, perhaps due to some internal changes. However, an update of the engine is extremely unlikely to have happened in 2020, and we know that Ford would have no qualms whatsoever about intentionally leaving the 2020 manual unchanged just to avoid admitting that they made a mistake. So, what should we do? Should we trust Ford and continue using 5W-20? Or should we trust or instincts and switch to 0W-30?

 

[EFI]

So, what should we do? Should we trust Ford and continue using 5W-20? Or should we trust or instincts and switch to 0W-30?

Highly depends on your usage. For daily driving on the street, there's no real reason to go away from what the manufacturer recommends. If you're going to be tracking the car and pushing the oil well beyond it's intended temperature range, then a thicker fluid is a no brainer.

I personally use 5w30 in the winter and 0w40 during the summer when I track the car. This was well before Ford officially went to 5w30 for street use.

 

[PoCoBob]

It could be as simple as Ford got tired of all the questions about low oil pressure at idle. Easy fix, use a heavier oil.

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