Ford: High altitude requires 0W oil. Why?

[SubieRubyRoo]

Odd. Why would they include altitude? Altitude and temperature are not always correlated. The world's highest mountains are near the equator.

I was a novice here too til a few years ago. I drove from Madera CA where it is very close to sea level, and was 98*. I went to Yosemite & drove up to Half Dome with the windows rolled up the whole way so I had no clue; roughly 6500’ elevation IIRC. By the time I got there, the temperature outside was 39*. I drove out the back highway of the park and down to Madera, where it was again 98*.

 

[Alien]

Note: is this a direct quote from the manual (emphasis mine)?
If you use your vehicle regularly above the altitude of 7500 ft (2,286 m) and under the temperature of -4.0°F (-20°C), it is recommended to use the alternative engine oil.

If so, it is logically incorrect. Clearly, if you're at sea level and it's below -4* F, then the thinner oil is appropriate no matter what your altitude is. The manual should say or, not and. Or just not mention altitude at all.

No, the manual does not recommend 0w oil at -4F at sea level. Only above 7500 feet. At sea level it requires 0W oil only below -22F. The question is why?

 

[Alien]

No, the manual does not recommend 0w oil at -4F at sea level. Only above 7500 feet. At sea level it requires 0W oil only below -22F. The question is why?

Just above the oil specifier, the manual states:

"Use oil that meets the defined specification and viscosity grade.
If you do not use oil that meets the defined specification and viscosity grade, it could result in:

• Component damage that your vehicle warranty does not cover."

It is not clear what would happen if an owner who lives in a sea level environment that never gets below -21F would be covered in the event of an engine failure if he was using 0W30 oil, since it is not "defined viscosity grade" for his temperature or altitude.

 

[MRC01]

No, the manual does not recommend 0w oil at -4F at sea level. Only above 7500 feet. At sea level it requires 0W oil only below -22F. The question is why?

Good question. That's just super weird.

 

[pdxglocker9mm]

It gets colder the higher you go. It’s that way no matter where you are on the planet. Hawaii’s tallest mountain has snow on top.

Yup
Went on a bike ride down haleakala on maui. They drove you up in the dark to see the sunrise Then you could ride like 20 something miles down hill with out peddling. There were also vans of people to just see the sunrise. Tons of the tourists were in flip flops, shorts and t shirts they were freezing their butts off at 5 am.

 

[kschachn]

One also has to consider that some of those oil grade charts can be the most neglected and obsolete sections in the owner's manual.

 

[kschachn]

Just above the oil specifier, the manual states:

"Use oil that meets the defined specification and viscosity grade.
If you do not use oil that meets the defined specification and viscosity grade, it could result in:

• Component damage that your vehicle warranty does not cover."

It is not clear what would happen if an owner who lives in a sea level environment that never gets below -21F would be covered in the event of an engine failure if he was using 0W30 oil, since it is not "defined viscosity grade" for his temperature or altitude.

The "component damage" being referenced here can occur from two instances. One is using an oil with an insufficient HT/HS or by using an oil with a winter rating that is wholly inappropriate for the expected starting temperature. Unless you are below -30 or so, an oil with a 5W winter rating will be pumpable and will not be the source of engine damage. So unless you are below that temperature then either a 0w30 or a 5w30 is more or less indistinguishable to the engine. Above 0F an oil with a 10W rating would also be appropriate. The altitude thing is not relevant to pumping and crankability which is what the winter rating represents.

 

[kschachn]

1) They still want the owners to use 5W if at all possible (meaning temperatures above -22F). Otherwise, why not just specify 0W30 for all temperatures as some other OEMs do. That tells me they have reason to believe that 5W oils are better than 0W oils at most temperatures and altitudes.

No, if the winter rating is appropriate for the starting temperature then it does not define oil performance during operation. That is determined by other properties of the oil. For example a 0w30 oil with certain European approvals (such as the old Castrol GC) has demonstrated superior performance than any ILSAC 5w30 without those approvals.

 

[Alien]

The "component damage" being referenced here can occur from two instances. One is using an oil with an insufficient HT/HS or by using an oil with a winter rating that is wholly inappropriate for the expected starting temperature. Unless you are below -30 or so, an oil with a 5W winter rating will be pumpable and will not be the source of engine damage. So unless you are below that temperature then either a 0w30 or a 5w30 is more or less indistinguishable to the engine. Above 0F an oil with a 10W rating would also be appropriate. The altitude thing is not relevant to pumping and crankability which is what the winter rating represents.

I understand the theory. But Ford, who has produced the most turbocharged GDI engines of any manufacturer and has a gigantic database of what actually works and what does not, disagrees. And they do think that the "altitude thing" is relevant, or they would not have included the recommendation in 2021 and 2022 Ecoboost user's manuals. The unanswered question is why?

 

[BornSlippy]

I'm going to guess it's related to the turbo charger(s).

 

[MRC01]

I'm going to guess it's related to the turbo charger(s).

If it's a turbocharged engine, then the turbo works harder at altitude to produce the same power with thinner air. Pressure loss at 7500' altitude is approximately 3 PSI, so if the turbo boost is 10 PSI at sea level it's 13 PSI at 7500'. Or you could say it's the same 10 PSI in absolute terms, but 13 PSI relative to ambient pressure.

However, this higher boost does not mean higher power, heat or temperature in the engine compared to sea level. It is working harder only to produce the same power it had at sea level. So 13 PSI at 7500' is roughly the same as 10 PSI at sea level.

 

[tcp71]

That might be a downgrade in shear stability and volatility.

Which may be true for Ford's "synthetic blend" recommendations, but a lot of euro 0w30 are significantly better than ILSAC 5w30s and meet much more stringent approvals.

 

[demarpaint]

All Ford had to do was say below a certain temperature use a 0W30 oil, meeting their spec. Why complicate simplicity? Was it some engineer trying to justify his pay grade?

 

[The Critic]

Which may be true for Ford's "synthetic blend" recommendations, but a lot of euro 0w30 are significantly better than ILSAC 5w30s and meet much more stringent approvals.

Correct, but then you are comparing apples to oranges. If we are comparing Mobil 1 Advanced Fuel Economy 0W30 to their normal 5W30, I'd argue that their 5W30 is a better choice for most situations.

 

[Snagglefoot]

Welp, when the oil pump starts the oil moving at sea level, there 14.7 psi of air pressure helping to feed the pump. At 7,000 ft elevation there is only 11 psi available. A thinner oil under those conditions would feed the pump easier. Does that work for anyone?

 

[ammolab]

Welp, when the oil pump starts the oil moving at sea level, there 14.7 psi of air pressure helping to feed the pump. At 7,000 ft elevation there is only 5 psi available. A thinner oil under those conditions would feed the pump easier. Does that work for anyone?

Actually 11.3 psi @ 7000 ft. The altitude at my house. Humans and ICE would not do good at 5psi air pressure

 

[Snagglefoot]

Actually 11.3 psi @ 7000 ft.

Thanks. I just corrected my error from reading the metric chart wrong. Here it is.

 

[BornSlippy]

Which may be true for Ford's "synthetic blend" recommendations, but a lot of euro 0w30 are significantly better than ILSAC 5w30s and meet much more stringent approvals.

WSS-M2C963-A1 pertains to a GF-6A 0w30 which a euro 0w30 does not meet.

There are three 0w30 ILSAC GF-6A oils that I know of;

Mobil 1 Advanced Fuel Economy
Pennzoil Maximum Power (Never seen it out in the wild)
Petro Canada Supreme Synthetic

I wouldn't hesitate to run a Euro 0w30 in an Ecoboost but since the topic of this thread is running an oil that Ford is recommending, it's sort of a moot point.

 

[MRC01]

Kudos to me for approximating the pressure loss at 7500' at roughly 3 PSI, off the top of my head without reference to a chart!
After converting units, the chart says it's about 3.2 PSI.
PS: none of this explains why the oil should be thinner at high altitude, due to altitude alone not the related temperature drop.

 

[Jetronic]

In the 2022 F-150 and Expedition owner's manuals Ford states: "If you use your vehicle regularly above the altitude of 7500 ft (2,286 m) and under the temperature of -4.0°F (-20°C), it is recommended to use the alternative engine oil", where the "alternative engine oil" is 0w30 instead of the normal 5w30. Why do you think altitude makes a difference?

Here is an excerpt from the manual:

Materials

Name	Specification
Engine Oil - SAE 5w30 - Synthetic Blend	WSS-M2C961-A1

Alternative Engine Oil for Extremely Cold Climates
To improve engine cold start performance, use the following engine oil in climates where the ambient temperature reaches -22.0°F (-30°C) or below.
Materials

Name	Specification
Engine Oil - SAE 0w30 - Synthetic Blend	WSS-M2C963-A1

Note: If you use your vehicle regularly above the altitude of 7500 ft (2,286 m) and under the temperature of -4.0°F (-20°C), it is recommended to use the alternative engine oil.

Cooling of the oil is less at elevation, 0w30 would contain more PAO and be more thermally stable than a group III 5w30. There's a higher viscosity index involved aswell, so viscosity drops less above 100°F. And higher loads are a given driving up to thos higher elevations.