Honest question about aviation oil

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Yes, its around 5-7 dollars a qt for Phillips xc, plus shipping. Can you provide me with an answer to my question?
Is this your real purpose in this thread to constantly ask that over and over again?

If you're not getting what you want then you're not getting what you want, but you don't need to keep being snarky about it.
 
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Just curious, what do you use? In my reading, Phillips xc seems to be very popular and it's quite a bit cheaper than aeroshell. Can you provide any insight on the topic of my question? I'm not seeing why, if an older car engine can operate fine in bon detergent oil, it couldn't operate fine with aircraft oil. 🤷‍♀️


I'll try to answer the question directly. Aircraft piston engine oils (for Lycoming/Continental and not Rotax) are high viscosity oils that work well in air cooled engines. With Aeroshell 100 being 230cst at 40c and 19.7 @ 100c. Such oils have no problem what so ever protecting an automotive engine through viscosity alone. We've used Aeroshell 15W-50 and Aeroshell 100 in car engines plenty of times with good results. But it's hot here in South FL. (no cold flow problems)

NOTE: Some aviation oils contain additives safe for aircraft engines using leaded fuel, and less than ideal for engines on unleaded.

Today's aviation oils may contain TCP, TPP or TCC (TriCresylPhosphate or similar) to provide some level of anti scuff protection. At the expense of dissolving seals and copper. So a copper anti corrosive is added.

I use Aeroshell 15W-50 most of the time in our fleet. Unless I know I won't be up in the cold weather. Then I use Aeroshell 100. Both get a splash of Camguard.
 

Astro14

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Yes, its around 5-7 dollars a qt for Phillips xc, plus shipping. Can you provide me with an answer to my question?
I wouldn’t use it in my classic car. That’s one of your questions.

There are better (and also cheaper) choices for a classic car.
 

Red91

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I'll try to answer the question directly. Aircraft piston engine oils (for Lycoming/Continental and not Rotax) are high viscosity oils that work well in air cooled engines. With Aeroshell 100 being 230cst at 40c and 19.7 @ 100c. Such oils have no problem what so ever protecting an automotive engine through viscosity alone. We've used Aeroshell 15W-50 and Aeroshell 100 in car engines plenty of times with good results. But it's hot here in South FL. (no cold flow problems)

NOTE: Some aviation oils contain additives safe for aircraft engines using leaded fuel, and less than ideal for engines on unleaded.

Today's aviation oils may contain TCP, TPP or TCC (TriCresylPhosphate or similar) to provide some level of anti scuff protection. At the expense of dissolving seals and copper. So a copper anti corrosive is added.

I use Aeroshell 15W-50 most of the time in our fleet. Unless I know I won't be up in the cold weather. Then I use Aeroshell 100. Both get a splash of Camguard.
Thank you. A little bit of knowledgeable information is all I asked for, and that's exactly what you offered. I appreciate it. I kind of got the impression that this kind of oil would be best suited to air cooled engines almost exclusively. I haven't had any intention of using it in my car, but I am considering splitting a bottle between a lawn mower and a pressure washer. If I had something like an old corvair, I'd probably try some in it too. 🤷‍♀️ I had not seen anything on the copper antioxidant, that's an interesting tidbit of info. Again, thank you.
 

Red91

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I wouldn’t use it in my classic car. That’s one of your questions.

There are better (and also cheaper) choices for a classic car.
Ok. I mean, I get that but you aren't saying why. You can't just say "I wouldn't do it" and leave it open ended like that. Offer something up. Is it the fast that it doesn't use common automotive detergents and additives? Is it because the most common viscosity is a 50wt? I mean, that would be something. Are we not discussing things on this forum anymore lol?
 
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Red91

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Is this your real purpose in this thread to constantly ask that over and over again?

If you're not getting what you want then you're not getting what you want, but you don't need to keep being snarky about it.
Why are you here again? You dont seem to care about the subject, nor the act of discussion. You dont know the answer to my question but you're still here, not providing anything. If you dont know and dont care about the subject, dont be a part of it. This is an oil forum and I had a question regarding oil that has taken some time to find an educated answer to. I would think that's relevant.
 
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Why are you here again? You dont seem to care about the subject, nor the act of discussion. You dont know the answer to my question but you're still here, not providing anything. If you dont know and dont care about the subject, dont be a part of it. This is an oil forum and I had a question regarding oil that has taken some time to find an educated answer to. I would think that's relevant.
Why do you keep posting the redundant question?

I did tell you that the aviation oil carries no PCMO approvals, licenses or certifications which make it inappropriate for use in a passenger car engine or even in OPE. Is that not relevant?

If you run it as a test no one thinks the engine will fail in short order. Kind of like running vegetable oil or some old API SA oil. What else do you want to see?
 

Astro14

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Ok. I mean, I get that but you aren't saying why. You can't just say "I wouldn't do it" and leave it open ended like that. Offer something up. Is it the fast that it doesn't use common automotive detergents and additives? Is it because the most common viscosity is a 50wt? I mean, that would be something. Are we not discussing things on this forum anymore lol?

The viscosity is too high. It lacks the correct detergents. It may be incompatible with the chemistry of additives in the oil I’m using. It has the chance of degrading copper components, and there are many on my car. It costs more.

So; pay more, get less and run risks...

Thanks, but I’ll pass.

You have some odd ideas about what should be used in a classic car. I’m not sure what you even mean by classic, but I wouldn’t put aviation oil in an older car, and I wouldn’t use it in a modern car.

Further, how do you even know that it “cools better” as you claim in your original post?

That strikes me as wild guessing, projection, or perhaps, trolling
 

Red91

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The viscosity is too high. It lacks the correct detergents. It may be incompatible with the chemistry of additives in the oil I’m using. It has the chance of degrading copper components, and there are many on my car. It costs more.

So; pay more, get less and run risks...

Thanks, but I’ll pass.

You have some odd ideas about what should be used in a classic car. I’m not sure what you even mean by classic, but I wouldn’t put aviation oil in an older car, and I wouldn’t use it in a modern car.

Further, how do you even know that it “cools better” as you claim in your original post?

That strikes me as wild guessing, projection, or perhaps, trolling
Not trolling. I'm genuinely curious so I'm asking questions. What you just listed as reasons why not is all I was asking for in the first place. The "cools better" comment was in reference to the oils duty to cool the engine just as well as it lubricates. If I'm not mistaken, I said something like "it almost seems as the oils ability to cool is more important than its ability to lubricate ", which wasn't meant to be taken as a direct opinion. One of the articles I read spent the majority of its space talking about the importance of cooling the engine, and must less on the oils lubricating properties.
 
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Red91

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Why do you keep posting the redundant question?

I did tell you that the aviation oil carries no PCMO approvals, licenses or certifications which make it inappropriate for use in a passenger car engine or even in OPE. Is that not relevant?

If you run it as a test no one thinks the engine will fail in short order. Kind of like running vegetable oil or some old API SA oil. What else do you want to see?
Lacking the approvals does not inherently make the lube inappropriate. It just means it hasnt been tested for those approvals. I'll give you that, its doubtful an aviation oil could pass much more than perhaps api sa, but I'm not talking about dumping the stuff in a gdi Kia or a turbo Ford. I'm talking some old clapped out ope that wont care anyway, or some old flathead lunk under the hood of a dilapidated Ford sedan. I made it clear this was all in reference to tinkering and experimenting, and was just seeking some baseline information. Reiterating what is constantly talked about in the pcmo section in regard to modern cars and engines tells me nothing I dont already know.
 
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All oils cool, but you'll have a tough time finding any valid test data that shows how the cooling performance is effected by viscosity and/or formulation. The difference if any is basically hair splitting IMO. Oil's main function is to lubricate first and cool second, or the engine isn't going to operate well. Thicker oil also generates more heat within itself as it shears between moving parts. So there are all kinds of factors going on at the same time as oil circulates through an engine and lubricates parts.
 
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The viscosity is too high. It lacks the correct detergents.

Here in South Florida, the Viscosity of 15W-50 Aeroshell is not too high for many older automotive engines. Aeroshell 15W-50 is said to be a 50/50 blend of PAO and conventional oil. PAO, as you know, flows quite well in cold conditions. When I fly to TN or PA in my 177RG, the 15W-50 has no problem flowing at temperatures far below freezing. It eliminates the need to pre-heat my engine.

Over the years, some aircraft in our fleet saw little or no use. The drain 15W-50 was still amber clear and was used in a BMW race car, Toyota pickup truck and my various clunkers, including a diesel rabbit. The old Toyota pickup probably used the most AS 15W-50 and is still running fine 20 years later. No problems experienced what so ever. No sludge either.

I'm not making the claim it's ideal. Only that it provides adequate protection.

No aviation thread is complete without a pic of a plane. My Cessna 177RG.

I44TTsX.jpg
 
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Red91

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All oils cool, but you'll have a tough time finding any valid test data that shows how the cooling performance is effected by viscosity and/or formulation. The difference if any is basically hair splitting IMO. Oil's main function is to lubricate first and cool second, or the engine isn't going to operate well. Thicker oil also generates more heat within itself as it shears between moving parts. So there are all kinds of factors going on at the same time as oil circulates through an engine and lubricates parts.
My understanding is the aviation oil is typically heavy because the clearances of aircraft piston engines are rather excessive to accommodate for expansion and retraction based on temperature. Oil consumption is practically a design feature, as its accepted that a certain amount per so many hours is a given.
 

Red91

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Here in South Florida, the Viscosity of 15W-50 Aeroshell is not too high for many older automotive engines. Aeroshell 15W-50 is said to be a 50/50 blend of PAO and conventional oil. PAO, as you know, flows quite well in cold conditions. When I fly to TN or PA in my 177RG, the 15W-50 has no problem flowing at temperatures far below freezing. It eliminates the need to pre-heat my engine.

Over the years, some aircraft in our fleet saw little or no use. The drain 15W-50 was still amber clear and was used in a BMW race car, Toyota pickup truck and my various clunkers, including a diesel rabbit. The old Toyota pickup probably used the most AS 15W-50 and is still running fine 20 years later. No problems experienced what so ever. No sludge either.

I'm not making the claim it's ideal. Only that it provides adequate protection.
I've been leaning towards Phillips xc, but I found out my local small airport carrys aeroshell in 100, w100 and 15w50. I didn't get pricing, but I imagine it would be cheaper to purchase aeroshell from them than to order Phillips and have it shipped, even though Phillips is cheaper on it's own. My studies have not indicated than either brand is superior, other than quite a few claims that Phillips reduced oil consumption over as. I dont necessarily believe consumption rate is indicative of the quality though.
 
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My studies have not indicated than either brand is superior,

From years and years of practical experience, I really can't tell a wear difference between any of the aviation oils. Other than the AS 15W-50 leaves somewhat fewer deposits under the valve cover. It seems to me, oil change frequency is far more important than brand.

These guys get 2380 turbine oil. During a recent engine "midlife" the BR710's looked perfect inside. So the 2380 worked just fine.


DZrPdNU.jpg
 
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