Do we really need 5w50?

[WildHorse]

Canada. Needs 5w.

No, the Ford engineers say Texas or Manitoba & everywhere in between you need 5W.

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[honeybadger]

Just to play devil's advocate.

Ya'll need to keep in mind that engineer's spec things (whether it be oil, tolerances, material, etc.) based on the broadest set of variables they have to. In this case, they needed an oil that worked in temps below freezing as well as track use. OEM specs have a metric F*** ton of compromises to make. Just because 5W-50 oil was spec'd doesn't mean that it's the best for his specific use case.

That said, the OEM stuff is damn good in almost all conditions and should meet the needs of pretty much everyone.

 

[datadatum]

^ This. If you asked the Ford engineer that wrote that specification, "what is the optimal oil?"... I guarantee you that the Ford engineer would ask 20 questions before making a recommendation very specific to the answers to the questions.

 

[fpGT350]

I don't see what there is to be gained by not following the factory spec for oil unless you are in a purely racing application.

 

[Hack]

My advice would be to use the oil recommended by Ford, at least until the warranty is up. 2 cents.

 

[Niz55]

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

 

[galaxy]

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

On a lighter topic...I just changed the oil in a friends IS350 that takes 0W20. After changing the oil in my ride twice, that shit was like pouring water!!!

I recall growing up, all the old engine builder guys in town used to say “run the lightest oil that you can stand the noise of!” Hahahhahahaha.

 

[TomcatDriver]

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

I have to assume this is a joke. That being said, the trend toward thinner oils is highly driven by CAFE standards. When Ford went from widely recommending 5W30 to 5W20 in the early 2000's there was no change to the engines. In fact Ford was still recommending 5W30 in overseas markets where 5W20 wasn't widely available. The same arguments about "the engineers know what they are doing" and "these new engines have tighter tolerances" were widely made, but the truth is that Ford got something like a 1.5% CAFE credit (not 1.5 MPG, 1.5%). I was only able to find one article with anything resembling an objective test, but that one article concluded that you were probably paying with that 1.5% with about 20-30% engine life compared to 30 weight, and since normal engines don't "wear out" until way after warranty, who cares. The reason most cars call for such light weight oil is all about CAFE numbers, and has little to do with what the engineers want. I switched my 5W20 cars to 5W30 and haven't looked back. If I had a regular Coyote I would be running 5W30.

 

[galaxy]

I bought a 2002 F150 right in the heyday of all the 20 weight drama. I made the decision while brand new to stick with the 30 because of such. But I know people with hundreds of thousands of successful miles on 20 weight with zero issues. At the end of the day, who knows!

 

[JAJ]

There was a lot of concern about 20 weight oils at first, but over the decade and a half since it became "normal", there's really no evidence that it's cost owners any engine life. If you drive 150,000 miles in a car that gets 20mpg, that 1.5% saves you about $400 in fuel costs, without any apparent need to spend any of it on extra repairs.

The way I think about the issue is that "the engineers" were given the task of improving fuel economy, and they implemented a wide array of new approaches like higher compression ratios, turbo's and direct injection as well as specifying lower viscosity oil, that provided that fuel economy improvement. They also gave us smaller and lighter engines with more power. I think they did a pretty good job, actually.

 

[Niz55]

2013 track pack gt required 5w-50 vs the none track pack. The only difference was the oil cooler. Same exact engine on both. The other ran 5w-20.

 

[nastang87xx]

You should probably replace your oil pan with this one too:

 

[AC53]

Unfortunately, as with all oil threads, everyone is an oil semi-expert and very few will back their assertions up with any credible data.

Ford doesn't specify anything higher than 5w-50 (for either number) for the engine. For their 5L they specify from a 0w-20 (fuel economy, light-use, use below -20F), 5w-20 for normal use and 5w-30 for racing/track-days.

Lots of folks chime in with questions about operating in areas where they are seeing ambient temperatures hit 100F and more. While this may seem like something unusual, it is completely normal for cars to be operating in areas (the Middle East, etc.) where the average daily highs are above 100F for several months at a time.

Here's what Ford says about using the GT350 in those environments:

"Hot Climate Oil Change Intervals
Vehicles operating in the Middle East or locations with similar climates using an American Petroleum Institute (API) Certified for Gasoline Engines (Certification mark) oil of SM or SN quality, the normal oil change interval is 3,000 mi (4,800 km)."

They do not say to use a 15w-50 nor should they. They say to change your oil more frequently, period.

For track use on the newest 5L engines, they tell you to go from a 5w-20 to a 5w-30. Again, they don't say to go to a 10w-30 nor a 15w-40, 15w-50 etc. Why??? Because they know what is best unless of course, you think you can build a virtually new high-performance car in record time, take it to LeMans and win first time out. Ford does a ton of testing with racing engineers that have as much or more technical and practical experience than most anyone you care to mention.

Do it if you want, but realize that you are not doing yourself any favours.

Far too many people don't understand the use of things and simply speak about what they think without any facts behind it. There are tons of that in every oil thread.

1) the 5w identifies two primary things (dealing with its viscosity and a few other things)

• how well the oil will flow in cold temperatures
• how well the oil will lubricate at start-up on a cold engine

2) the 50 in a 5w-50 identifies one main thing

• the viscosity of the oil at 100C (212F)

There is a great deal of engine wear that occurs at startup. the lower the viscosity the less wear, up to a point (many feel that 5w is about the right point for today's engines and anything below increases wear but that is another story). These considerations are always trade-offs between power, wear, economy, and emissions.

Anyone who has even a basic understanding of engine oil will know that going from a 5w-50 to a 15w-50 (fully synthetic, top-tier) gives you absolutely no additional protection from high temperatures. All it does is change to oil that does not flow as quickly until it reaches full operating temperature. Remember, this is where we encounter accelerated wear (just like we do at the upper reaches of an engine's rpm limit).

Even if one is fine with a bit of additional wear, the problem is that there is no actual benefit for doing that and there are additional problems introduced.
1) Heat protection comes from the 50 in a 5w-50
2) These engines use Ford's Ti-VCT (variable valve timing). This system relies on a fast oil flow to work properly.

Who in their right mind would triple (15w-50 vs 5w-50) the oil viscosity from Ford's specs for absolutely no demonstrated gain??? (more like a sliding scale of triple at startup until identical when fully warm)

Finally, most of the concerns you hear are carryovers from the types and quality of oils that were used decades ago. Very little has to do with the quality of current top-tier fully-synthetic oil. There used to be an issue with say a 5w-30 mineral oil versus a 10w-30 and this was partially true for the original synthetic oils as well. The issue was that the first number (5 or 10) represented the base-stock and therefore the overall quality of the oil and how well it would hold its viscosity at higher temperatures. This was, and still is, very true of mineral oils but the new synthetic oils have eclipsed these issue for all practical purposes. As an end-note, you will see that nowhere does it call for anything higher than a 50 in the 5w-50, 0w-20, 5w-3=20, 5w-30, etc. The reason for this is that if you are running hotter than a 5w-50 can handle, you have something work that needs to be addressed.

 

[activeGT]

Unfortunately, as with all oil threads, everyone is an oil semi-expert and very few will back their assertions up with any credible data.

Thank you, sir, for an intelligent response to a question I was sincerely asking about. I now will use the 5-50 based on your post. It makes sense to me.

 

[JAJ]

Unfortunately, as with all oil threads, everyone is an oil semi-expert and very few will back their assertions up with any credible data.

Ford doesn't specify anything higher than 5w-50 (for either number) for the engine. For their 5L they specify from a 0w-20 (fuel economy, light-use, use below -20F), 5w-20 for normal use and 5w-30 for racing/track-days.

Lots of folks chime in with questions about operating in areas where they are seeing ambient temperatures hit 100F and more. While this may seem like something unusual, it is completely normal for cars to be operating in areas (the Middle East, etc.) where the average daily highs are above 100F for several months at a time.

Here's what Ford says about using the GT350 in those environments:

"Hot Climate Oil Change Intervals
Vehicles operating in the Middle East or locations with similar climates using an American Petroleum Institute (API) Certified for Gasoline Engines (Certification mark) oil of SM or SN quality, the normal oil change interval is 3,000 mi (4,800 km)."

They do not say to use a 15w-50 nor should they. They say to change your oil more frequently, period.

For track use on the newest 5L engines, they tell you to go from a 5w-20 to a 5w-30. Again, they don't say to go to a 10w-30 nor a 15w-40, 15w-50 etc. Why??? Because they know what is best unless of course, you think you can build a virtually new high-performance car in record time, take it to LeMans and win first time out. Ford does a ton of testing with racing engineers that have as much or more technical and practical experience than most anyone you care to mention.

Do it if you want, but realize that you are not doing yourself any favours.

Far too many people don't understand the use of things and simply speak about what they think without any facts behind it. There are tons of that in every oil thread.

1) the 5w identifies two primary things (dealing with its viscosity and a few other things)

• how well the oil will flow in cold temperatures
• how well the oil will lubricate at start-up on a cold engine

2) the 50 in a 5w-50 identifies one main thing

• the viscosity of the oil at 100C (212F)

There is a great deal of engine wear that occurs at startup. the lower the viscosity the less wear, up to a point (many feel that 5w is about the right point for today's engines and anything below increases wear but that is another story). These considerations are always trade-offs between power, wear, economy, and emissions.

Anyone who has even a basic understanding of engine oil will know that going from a 5w-50 to a 15w-50 (fully synthetic, top-tier) gives you absolutely no additional protection from high temperatures. All it does is change to oil that does not flow as quickly until it reaches full operating temperature. Remember, this is where we encounter accelerated wear (just like we do at the upper reaches of an engine's rpm limit).

Even if one is fine with a bit of additional wear, the problem is that there is no actual benefit for doing that and there are additional problems introduced.
1) Heat protection comes from the 50 in a 5w-50
2) These engines use Ford's Ti-VCT (variable valve timing). This system relies on a fast oil flow to work properly.

Who in their right mind would triple (15w-50 vs 5w-50) the oil viscosity from Ford's specs for absolutely no demonstrated gain??? (more like a sliding scale of triple at startup until identical when fully warm)

Finally, most of the concerns you hear are carryovers from the types and quality of oils that were used decades ago. Very little has to do with the quality of current top-tier fully-synthetic oil. There used to be an issue with say a 5w-30 mineral oil versus a 10w-30 and this was partially true for the original synthetic oils as well. The issue was that the first number (5 or 10) represented the base-stock and therefore the overall quality of the oil and how well it would hold its viscosity at higher temperatures. This was, and still is, very true of mineral oils but the new synthetic oils have eclipsed these issue for all practical purposes. As an end-note, you will see that nowhere does it call for anything higher than a 50 in the 5w-50, 0w-20, 5w-20, 5w-30, etc. The reason for this is that if you are running hotter than a 5w-50 can handle, you have something work that needs to be addressed.

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

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.

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. 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. 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.

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