Do we really need 5w50?

[TehEno]

I got a supercharger installed, Tickford, Roush and Ford said to use 5W50. So I use 5W50.

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[Walt Kowalski]

If you have sponsored quality oils it’s a great OP.
I’ve still got heaps of great oils from my race car that I haven’t used in any of my last 5 S550’s.
So I’m following with interest.

What engines in race boats?
Pics of boat please.
Or girlfriend.

 

[Walt Kowalski]

AC53. ThanQ! Best post in this forum I’ve seen.

And OP yeah. More Border Controls everywhere not just Texas. Texas a good start though. Australia finally has a (fairly non Globalist) leader who is enforcing our borders.

WWG1WGA

 

[MikeR397]

I use 0w-20 for better gas milage. Works great and inexpensive buying from Walmart.

You’re funny. I drank an entire tank of gas two weeks ago with 2 30 min track sessions. Then did it again.

 

[honeybadger]

Only semi-related, but I have 14quarts and a spin on filter type if anyone is interested in a deal

 

[AC53]

Good effort but there are a couple of places where a bit more precision would have been helpful:...

Didn't want to make it into novel-length if possible. ;-)

... First, the Hot Climate Oil Change Intervals statement actually has two qualifiers - the first is climate ("Middle East or locations with similar climates") and the second is oil quality - API SM or SN, which may fall short of WSS-M2C9XX-YY. In other words, if you're using Ford qualified oil, just go by the OLM regardless of climate, but if you can't get Ford qualified oil in the country you're in, then use API SM or SN and change it every 3000 miles...

My thoughts there are that, the driving factor for "climate" is heat which has a direct bearing on what is an appropriate viscosity oil for any specific application. The spec for the GT350 is WSS-M2C931-B, so you'd ideally want something compliant with that or higher (C, or D). But that's really no issue, most top-tier brands that I'm aware of have it available, Shell, Mobil-1, Castrol, Amsoil, Valvoline, etc.

My purpose of including the "Hot Climate" info was to help address the OP's concern and dispel the myth of other posts that a 15w-50 provided additional "needed" protection in high-temperature environments then a 5w-50.

... Second, the 5W or 15W has nothing to do with viscosity directly. It designates the cold temperature at which the oil's viscosity rises above a specific threshold - 6600 mPa-s at -30C (-22F) for 5W and 7000 mPa-s at -20C (-4F) for 15W...

I would suggest that "the 5W or 15W" has everything to do with viscosity as that is exactly what the 5 and 15 are referring to and what has been measured. 5w is measured at a different temperature than 15w, but the 5 and the 15 are the viscosity of the oil at their respective measured temperatures. A 5w-50 oil has a viscosity of 5 at the pre-defined cold measure temperature.

... At the temperatures that most of us use our cars in, freezing or above, the viscosities of 5W and 15W oils can be different or they can be the same - it's up to the formulator...

Agreed, if you are referring to different oils, however, if you are comparing the same oil just different weights, then they will have different properties throughout their temperature range. Have a look at the last page of this file: https://www.amsoil.com/lit/databulletins/g2880.pdf

The primary difference, for our purposes, between a 5w-50 and a 15w-50 of the same oil is that the 5w-50 will flow much better at cold startup and through to getting up to full operating temperature. If one uses a quality oil temperature gauge it becomes apparent that for most cars it takes at least 10 minutes of driving for the oil to actually get up to full operating temperature.

... There is a deeply held belief that in track use, an oil with a smaller viscosity range will perform better - it'll shear less, specifically. As you point out, that's based on information going back decades and may not be true any more. And the real gotcha is that the modern Ford ECU has guardrails in it to keep the engine running inside the design envelope, so no condition (other than long-term idling) is really extreme any more. The harder you work the engine, the faster the OLM counts down, but that's about it.

I think that holds true as a general rule, but one that really isn't necessary to follow. I have seen quality top-tier oils that have better #'s than the same oil with a smaller range but same "hot" viscosity. All depends on the specific oil.

The real point, however, is that there is a specific level of protection spec'd and just so long one provides that level of a bit more one should be fine. For instance Ford specs SAE 5W-50 full synthetic oil meeting Ford specification WSS-M2C931-B. The WSS-M2C931-B spec is something like a decade old now (brought in to address the needs of some specific European Ford engines) and has since been superseded by WSS-M2C931-C and then by WSS-M2C931-D. Ford could have spec'd the "C" or "D" but didn't. The logical conclusion we should draw from this is that those improvements (C&D vs B) are not needed for the 5.2L or they would have simply spec'd them as they have for other vehicles. Just like they could have spec'd 15w-50 for racing like they have spec'd 5w-30 for the Mustang GT under racing conditions vs its normal 5w-20 spec.

 

[EFI]

So what exactly are you going to gain by using 15w50 in your climate?

You're right, 5w is probably not really needed when the outside temps are 100*, but what exactly will you gain by going 15w?

 

[AC53]

So what exactly are you going to gain by using 15w50 in your climate?

You're right, 5w is probably not really needed when the outside temps are 100*, but what exactly will you gain by going 15w?

My mentioning the 15w-50 was in response to earlier posts recommending going to it for places like Florida and Texas rather than staying with the spec'd 5w-50.

I don't see that you would gain anything, but you would definitely be giving up protection during warmup and putting a strain on your VVT.

While a good part of the initial drive to quality 5w-xx and 0w-xx oil was for reduced emissions and improved fuel economy, it has also played a big part in helping VVT technology work as well as it has. These systems work on the very fast movement of small quantities of oil, to vary the cam timing, which requires a low viscosity or a very high pressure. Ford chose low viscosity as have others as it sucks off less power and puts less strain on the components which leads to greater longevity with fewer failures.

 

[Droopy1592]

Only semi-related, but I have 14quarts and a spin on filter type if anyone is interested in a deal

My nipples are hard

 

[honeybadger]

My nipples are hard

Should have seen when I was doing a break-in and had like 12 gallons of oil in the cabinet

 

[Andy13186]

So what exactly are you going to gain by using 15w50 in your climate?

You're right, 5w is probably not really needed when the outside temps are 100*, but what exactly will you gain by going 15w?

I dont think anything at all would be gained by going from 5w50 to 15w50, I think it would actually just be harder on the engine while cold out and take longer to warm up. Going to 0w40 may free up some HP and also make cold starts easier on the car but usually people dont go lighter than recommended on the oil.

 

[Droopy1592]

Should have seen when I was doing a break-in and had like 12 gallons of oil in the cabinet

Well? Price?

 

[honeybadger]

Well? Price?

PM sent

 

[Phoenix]

PM sent

i thought that was for my oil change when im (inevitably) back down there in 5 months?

 

[honeybadger]

i thought that was for my oil change when im (inevitably) back down there in 5 months?

hehe. I am doing some mid-summer cleaning and need to get them gone so I can get my garage and house back in control. 2 rooms are filled with car parts!

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