What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Auto fuel why not auto oil?

N24YW

Well Known Member
I was just thinking. If I run a lot of auto fuel in my engine would it not make more sense to also run a automotive oil. I think some of the additives in Aviation are to help offset the bad effect of lead in the fuel. With 15-50 at 6.30 a quart I was wondering what would happen if I ran a 15-50 racing oil.

Jim Knight
Burlington Iowa
RV-6 350 hours
 
Don't even think about it!!

Automotive oils are formulated for close tolerance water cooled engines. Aircraft engines are air cooled and have much larger tolerances. That makes the requirements for the lubricating oil unique to their genre.

Martin Sutter
Building and flying RV's since 1988
 
Many of the auto oils are better at reducing friction but can't handle the lead. Since you are using unleaded that problem would not be a problem. The second issue is many of the friction reducers will form ash deposits as the air cooled engine is designed to burn some oil. That problem will be a problem and it can be a big problem. Don't do it.
 
I seem to remember reading an article which stated that the additives in automotive oils are corrosive to the metals used in aircraft engines.

However, in the quick search I performed, I couldn't find any reference to that.

Mel, Mahlon - comments?
 
While I am completely ignorant on aircraft air-cooled engines, my Porsche 914 engine (also air-cooled 4-banger) had no issues with regular automotive oil.

I know a lot of motorcycle owners that would disagree with you. Lots of VW bug owners would also be happy to join with them.
 
AD oil

Aircraft engine lubricants contain special additive packages to handle the lead intrusion as well as a dispersant to suspend the ash deposits. Clearly automotive lubricants, although very advanced these days, do not meet these special requirements. Best to use the recommended lubricants in your engine.

Regards,
Chris
 
Why take a chance for so little gain?

I'm not an oil expert, but it seems to me that at best, the issue of using auto oil is contraversial and at worst, dangerous and possibly expensive.

Why would you want to risk a very expensive motor and possibly your life to save a few bucks on oil.

Makes no sense to me....


Jesse Bentley
RV-8

Muskego, WI
 
Why would you want to risk a very expensive motor and possibly your life to save a few bucks on oil.

Because everyone asks the question - is aviation oil more expensive because it's different and more expensive to produce, or is it just because it can?

I'm neither an oil expert nor I suggest using auto fuel in your bird, but sometimes I have that feeling that we, pilots and owners are treated by manufacturers as 'rich boys club' and many things cost.

And to make things worse:
If auto fuel than what grade/class? diesel/gas? synthetic/mineral/blended? branded/store branded? etc...

This topic can get even hotter than the one about leaning :)
 
This topic has been hammered about as many times as the topic of whether to prime aluminum or not.

Lycoming, AvWeb, and others have articles about the differences in auto oil and aviation oil. Last time I researched the topic, they seemed to make sense to me so I stuck with aviation oil. As I recall, they are different and there are some important reasons for that. I went to the Lycoming site to see if I could find the articles but they recently reorged their site and I couldn't find it quickly.

It's a good, valid question. You'll either believe the answers or not. In this case I don't believe it is a case of overcharging because they can, but I'd love to be proven wrong on that!;)

Check out this thread: http://www.vansairforce.com/community/showthread.php?t=23347&highlight=auto+oil
 
Last edited:
Check out the AeroShell (Shell Oil Co.) web site,
Look for the Piston Engine Oils pdf in their AeroShell Book section...
and there you will find an 11 page document on oils, applications, grade differences (example: aviation grade 80 = SAE grade 40), and why one should not use aviation specified oils in auto engines...and also the opposite.
 
I know someone who uses motorcycle oil, which I suppose is formulated for air cooled engines.

Personally, I agree with those who think that aircraft engines are too expensive to risk for the possible savings of a few hundred dollars over the life of the engine.

Also, think about resale value. If a buyer knows you have been using anything other than aircraft oil, do you suppose he/she will be willing to pay as much for the aircraft? You might lose all your savings and more when it is time to sell.
 
I just paid 4.95 per quart. Case of 12.This is what ECI uses as break in oil. And full time oil.

Phillips 66® X/C® 20W-50

X/C 20W-50 is the first approved multiviscosity aviation oil for opposed piston engines. It provides better engine performance than any single grade oil in all weather conditions. X/C 20W-50 is formulated with an ashless dispersant package allowing for cleaner engine operation. X/C 20W-50 is recommended for break-in. It provides a cleaner and quicker break-in than traditional all mineral single grade oils. Plus, X/C®is an operational oil so there is no need to switch oils after break-in. X/C 20W-50 utilizes all petroleum base oils which provide excellent solvency and is successful in preventing lead and lead salts.

Take advantage of X/C 20W-50’s multiviscosity performance benefits year-round for easier starts and quicker flow of oil to critical engine parts.

Package Availability: 55-gallon drums, 4/1 gallon jugs, 12/1quart.
 
I know someone who uses motorcycle oil, which I suppose is formulated for air cooled engines.

Not really. A lot of motorcycles use an oil bath clutch system. The difference is "motorcycle" oil has additivies that help prolong the clutch and for easy of operation.
 
I just paid 4.95 per quart. Case of 12.This is what ECI uses as break in oil. And full time oil.

Phillips 66® X/C® 20W-50

X/C 20W-50 is the first approved multiviscosity aviation oil for opposed piston engines. It provides better engine performance than any single grade oil in all weather conditions. X/C 20W-50 is formulated with an ashless dispersant package allowing for cleaner engine operation. X/C 20W-50 is recommended for break-in. It provides a cleaner and quicker break-in than traditional all mineral single grade oils. Plus, X/C®is an operational oil so there is no need to switch oils after break-in. X/C 20W-50 utilizes all petroleum base oils which provide excellent solvency and is successful in preventing lead and lead salts.

Take advantage of X/C 20W-50’s multiviscosity performance benefits year-round for easier starts and quicker flow of oil to critical engine parts.

Package Availability: 55-gallon drums, 4/1 gallon jugs, 12/1quart.

Be aware that Lycoming only recommends regular oil for engine break-in on only a couple of specific engine models. For everyone else, you should use mineral oil. I was researching the topic on the Lycoming web site as a result of this thread, FWIW. After break-in, I use the Phillips X/C 20W-50W and it is what my engine oil analyzer recomended too!
 
Not really. A lot of motorcycles use an oil bath clutch system. The difference is "motorcycle" oil has additivies that help prolong the clutch and for easy of operation.
And, for the Rotax flyers amongst us, motorcycle oil has anti-foaming agents that are helpful for the 912's gearbox, which uses the same oil system as the engine. Penzoil motorcycle oil works well, and the new AeroShell Oil Sport Plus 4 (what a name!) is a semi-synthetic that works well if you burn mostly mogas but some 100LL.

TODR
 
Seems like a lot of FUD

Fear, uncertainty, and doubt

Why is this not about temperature, RPMs, and clearances? Oil doesn't know if its flying or not.

I'm not knowledgeable about oil or engines, and I don't find oil to be a major cost overall, so I'm not motivated to experiment.

Someone should though so we can all benifit:)

Tangentially related:
2000 hr TBO x 150mph = 300,000 miles

That's a low average speed for an RV. For all the whining about the outdated "Lycosourous", I'd like to see one factory auto engine that could run that many miles at the high power settings we use. Even if the average Lyco only went half that long I think its a major feat.
 
Why would you think of that.

My last name is Brink, I am of Dutch descent.

Yes I can be cheap. But I still expect quality (that's the dutch part).

The long term economy is what I am after. I am not a lubrication engineer, but for the price difference in the oil, my belief is to go with the recommended tried and true.

Remember, surprises in aviation are typically not a good thing:eek:
 
food for discussion

I know some guys that ran Amsoil in their 540's, and after 25 hours when you'd expect the oil to start turning black it was still nice and clear.

With that said I was once told by a Phillips lubrication engineer that if we got rid of the lead in our oil, there's no reason we couldn't use a full synthetic oil. One reason for dispersants in our oil is for lead suspension.

I use Mobil 1 full synthetic in our cars, and in particular my diesel car, uses Mobil 1 Truck and SUV. The change interval with that stuff is 10K miles.

I for one welcome the demise of 100LL, so we can switch to more modern formulations. I think 100hr change intervals would be a good thing.
 
Fear, uncertainty, and doubt

Why is this not about temperature, RPMs, and clearances? Oil doesn't know if its flying or not.

I'm not knowledgeable about oil or engines, and I don't find oil to be a major cost overall, so I'm not motivated to experiment.

Someone should though so we can all benifit:)

Tangentially related:
2000 hr TBO x 150mph = 300,000 miles

That's a low average speed for an RV. For all the whining about the outdated "Lycosourous", I'd like to see one factory auto engine that could run that many miles at the high power settings we use. Even if the average Lyco only went half that long I think its a major feat.


I agree, oil does not know what engine it is in however there may be some truth to the synthetic oil/ lead idea. Mobil oil engineers confirmed the concern in an E-mail to me. I've been using Mobil 1 in the Subaru for 5 years and believe at about the 200 hour mark, lead started to jam up the rings, manifested by a slow drop in compression and an increase in oil consumption.

About 20 hours ago, I switched to Aeroshell 20/50. Oil consumption has stopped increasing and there is less oil coming from the breather. The compression test next month may shed some more light on the subject.

People have run Mobil 1 in Lycomings with no issues on auto fuel however it is about the same price as Aeroshell around here. Conventional auto oil is certainly less expensive but I don't think I'd use it in a Lycoming until well proven by someone else.

BTW, Don Parnham in Oklahoma, who does Gyro training routinely, sees Subarus going 2000+ hours with no maintenance other than cam belts. One Gyro training fellow in Oz reported 3800 hours this Spring on an EJ22 and it was still going strong.
 
The best use for aviation oil is for lubricating door hinges that squeak. I have worked for Imperial Oil (EXXON)for over 30 years. 10 in R&D and 20 in quality assurance. Use XD3 15w40 and never look back. Keeps the interals spotless without making combustion chamber deposits. It could make deposits if your burning copious amounts of oil but under normal oil consumpsion rates the deposit theory is a myth. I have seen lycomings apart (not from using the wrong oil , just some inferior/poorly desighned wrist pin buttons) at 1000 hrs. that had 0 deposits or wear anywhere and looked as clean as the day it was assembled. One engine was using Mobil 1 5w30 and the other was using XD3 15w40. Other engines I have seen apart that were using AV oil were full of coke deposits and were filthy inside. All the voodoo aside, I use XD3 15w40 in all my tractors,my truck, my car,offshore,combine,my lawnmower, and my RV-6 (IO-360) without any problems or worries. Oil companies love to make you feel special with all those special products. I don't use it because it's cheaper, I use it because it gives better protection to my motor and that is a fact. P.S. I won't write back to argue because I don't have to.
 
I'd be worried about gumming up and sticking the rings for starters. Car oils aren't designed to burn (as mentioned above). By the time you get a high enough quality auto oil, at $5+ a quart, you mind as well buy aeroshell at $6...

My 2?

We run Redline Racing 50w synthetic in the Formula 1, Continental O-200, running 100LL. But thats a VERY life-limited engine, comes apart every 20-30 hours. No noticeable deposits, but then again, we're running pretty tight tolerances, I don't think we get much blow-by at all. :).
 
The best use for aviation oil is for lubricating door hinges that squeak. I have worked for Imperial Oil (EXXON)for over 30 years. 10 in R&D and 20 in quality assurance. Use XD3 15w40 and never look back. Keeps the interals spotless without making combustion chamber deposits. It could make deposits if your burning copious amounts of oil but under normal oil consumpsion rates the deposit theory is a myth. I have seen lycomings apart (not from using the wrong oil , just some inferior/poorly desighned wrist pin buttons) at 1000 hrs. that had 0 deposits or wear anywhere and looked as clean as the day it was assembled. One engine was using Mobil 1 5w30 and the other was using XD3 15w40. Other engines I have seen apart that were using AV oil were full of coke deposits and were filthy inside. All the voodoo aside, I use XD3 15w40 in all my tractors,my truck, my car,offshore,combine,my lawnmower, and my RV-6 (IO-360) without any problems or worries. Oil companies love to make you feel special with all those special products. I don't use it because it's cheaper, I use it because it gives better protection to my motor and that is a fact. P.S. I won't write back to argue because I don't have to.

Bout time someone chimed in with actual knowledge on this stuff.
Doug, so its your experience that the XD3 out performed the aviation oils? No wear and a cleaner engine?

Googling, I see a lot of references to XD-3 oils from other oil company names. Esso, Kendall, Mobil, etc. Are these the same oils under a different name?
 
Oil, fuel, etc.

Like others posting here, I am not a lubrication engineer. For that matter I am not any type of engineer. And, I did not sleep in a Holiday Inn last night either, so the statements below can be taken for what they are worth.

Being the skeptic that I am, brand names, model types, company brands, etc. are all created to sell products (read increase revenue for the seller). They are not created to increase performance, reliability, or any other measure of efficiency we can think of. Brand loyalty is a very important tool used in the retail world to increase profits. Once we become sucked into the brand loyalty mentality we begin clouding our minds with silly ideas that nothing new could ever come along to do what MY product can do. However, it is the performance qualities that should be more important to us gear heads.

The concept that there is something unique and special about our aviation oil really plays into the hands of the corporate advertisers. They will continue to do everything in their power to keep consumers thinking down the lines of brand loyalty.

From what I hear in the posts here and elsewhere, there is the fact that the aviation oils do protect against lead buildup. Well, I have no reason to believe otherwise. However, there is not much else being discussed concerning what other vitally important service a particular brand or type of aviation oil is doing better or even just differently than any other type of oil (Bear in mind I am not discussing here the different viscosity weights of the various types of oil. I am only discussing the perceived differences between aviation oil and other types of oil.).

So, if this is the case, what happens when an aviation engine stops using leaded fuel? What technical argument will then exist to support using aviation labeled oil over any other branded type of oil?

Concerning the air cooled vs water cooled issue, it seems to me the water cooled engine would have much closer tolerances than the air cooled engine. Therefore, the oil had better be able to dissipate heat buildup that could occur in such tight quarters. If this is so, I would expect any oil produced for this environment to have better friction reduction and heat transfer qualities.

Several individuals have mentioned the burning of oil. Is it possible to burn oil without leaving residue on the pistons, rings, etc.? I would speculate that regardless of the market the oil is being pushed toward there are several companies that are selling an oil that would burn cleanly.

Now, having said all of this, here is my thinking (I know, I know, who cares what I think!). This is a small part of the expense of owning and operating your own aircraft. So I will not experiment with my engine oil and use whatever is recommended by the engine manufacturer. However, if we are honest with ourselves and I, in turn, am honest with myself, we must admit that almost all of us are using whatever brand, viscosity weight, type of oil we use, mostly based upon what someone else recommended or told us we should use. Our decisions are not based upon any type of scientific investigation about the best oil to use. We base our decisions on what our friends, family, mechanic, or sales men tell us we should do.

Well, my thoughts on the matter (I know, I know, who cares what I think!)!
 
Last edited:
<<Bout time someone chimed in with actual knowledge on this stuff.>>

Yes indeed. Doug, please share more.
 
Excellent

In my heart of hearts I've always known the "Aviation oils are for planes and motor oil is for cars" argument has been steeped in the same kind witchcraft that has prevented the adoption of the use of mogas.

As a delighted user of mogas (even mogas with ethanol) I can say that it takes time to work through the technical arguments and make an informed decision.

For mogas it was primarilly vapour lock..For auto oil I was wondering what was so different?...Different bearing material on the crank for instance.

Sounds like we have some real world knowledge that shows most of the arguments are pure bunk.

The lead in the fuel maybe an argument..but hey if you mostly run mogas than that argument goes away too.

I can hardly wait to use up my case of 100W..:)

Frank
 
The best use for aviation oil is for lubricating door hinges that squeak. I have worked for Imperial Oil (EXXON)for over 30 years. 10 in R&D and 20 in quality assurance. Use XD3 15w40 and never look back. Keeps the interals spotless without making combustion chamber deposits. It could make deposits if your burning copious amounts of oil but under normal oil consumpsion rates the deposit theory is a myth. I have seen lycomings apart (not from using the wrong oil , just some inferior/poorly desighned wrist pin buttons) at 1000 hrs. that had 0 deposits or wear anywhere and looked as clean as the day it was assembled. One engine was using Mobil 1 5w30 and the other was using XD3 15w40. Other engines I have seen apart that were using AV oil were full of coke deposits and were filthy inside. All the voodoo aside, I use XD3 15w40 in all my tractors,my truck, my car,offshore,combine,my lawnmower, and my RV-6 (IO-360) without any problems or worries. Oil companies love to make you feel special with all those special products. I don't use it because it's cheaper, I use it because it gives better protection to my motor and that is a fact. P.S. I won't write back to argue because I don't have to.

All what you say may well be true, Doug, but from a practical point of view having just purchased a Lycoming engine under warrantee, I must use the oil the company recommends or the warrantee is no good.

Just stuff to think about before going off to your local auto parts store for some of their oil....
 
Also a consideration is that mineral oil is a better rust preventative than the fully synthetic stuff [or so ive often been told]. As aero engines are used more infrequently , this may be a reason to stay with a w100 ?
 
Anyone using XD3 15w40?

Reviving this thread.

Have any others adopted this oil for use in their Lycoming?

If yes,
please state the Lycoming model number.
please state which fuels you use, auto, 100LL other.
please state time between oil changes.
please state oil consumption between changes.
please state approx. number of hours running this oil.
please state any known/perceived changes running this oil such as cleaner/dirtier cylinders, aircraft under belly, any failures caused by the oil etc.

Bevan
 
Thanks for your comments Doug. It sounds like you have an inside perspective. I realize you may not be able to share, but what data is available that we can sink our teeth into? Can you point us to anything objective? Not at all am I trying disparage. I just like to always understand ?why?.

Thanks!
Don

The best use for aviation oil is for lubricating door hinges that squeak. I have worked for Imperial Oil (EXXON)for over 30 years. 10 in R&D and 20 in quality assurance. Use XD3 15w40 and never look back. Keeps the interals spotless without making combustion chamber deposits. It could make deposits if your burning copious amounts of oil but under normal oil consumpsion rates the deposit theory is a myth. I have seen lycomings apart (not from using the wrong oil , just some inferior/poorly desighned wrist pin buttons) at 1000 hrs. that had 0 deposits or wear anywhere and looked as clean as the day it was assembled. One engine was using Mobil 1 5w30 and the other was using XD3 15w40. Other engines I have seen apart that were using AV oil were full of coke deposits and were filthy inside. All the voodoo aside, I use XD3 15w40 in all my tractors,my truck, my car,offshore,combine,my lawnmower, and my RV-6 (IO-360) without any problems or worries. Oil companies love to make you feel special with all those special products. I don't use it because it's cheaper, I use it because it gives better protection to my motor and that is a fact. P.S. I won't write back to argue because I don't have to.
 
Reviving this thread.

Have any others adopted this oil for use in their Lycoming?

If yes,
please state the Lycoming model number.
please state which fuels you use, auto, 100LL other.
please state time between oil changes.
please state oil consumption between changes.
please state approx. number of hours running this oil.
please state any known/perceived changes running this oil such as cleaner/dirtier cylinders, aircraft under belly, any failures caused by the oil etc.

Bevan
Here is a reference on the oil viscosity availability, and some additives.

You might add cam wear experience to your list if the user has slipper followers.
 
Aircraft oil

Aero oils are ,as others pointrd out, ashless dispersent oils designed for high stress aircooled engines with high CHT's and larger clearances.
 
Old thread. Apparently the referenced XD3 15W-40 is no longer available, at least by that brand name.
 
Old thread. Apparently the referenced XD3 15W-40 is no longer available, at least by that brand name.

XD3 is apparently the Mobil 1 series of oils. I attached a table of the viscosities and some additive concentrations of Mobil1 above. It does have ZDP but still may or may not be satisfactory for the slipper cam materials in the Lyc. It actually looks like the racing oil might compare best. A discussion with Mobil might help narrow the choices.

Each engine may be specific as to the additives needed, and engine developers can not test with every oil. If they only recommend one to keep warranty, then they legally have to supply that oil free. This is why (I believe) that new cars have free oil changes for a certain period. Not a bad marketing ploy either.

BTW - anyone heard of the chicken tax? It's why all pickup trucks are made in USA.
 
It does have ZDP but still may or may not be satisfactory for the slipper cam materials in the Lyc.

This is the kicker. Slider cam motors need Zinc dialkyldithiophosphate (ZDDP) in far greater amounts than roller cam motors (which need none). It helps keep the rubbing metals apart best.

The only oil you can still get on the auto market these days with the amount of Zinc a slider needs is diesel truck oil. Its what I run in all my older cars. And its what we'll need for our Lycos when we finally go no-lead.

Google and read. Lots and lots to read on this.
 
Chicken Tax ?

OK, I give up....what is the Chicken Tax ans what makes you think all pick up trucks are made in USA ?

;-)


XD3 is apparently the Mobil 1 series of oils. I attached a table of the viscosities and some additive concentrations of Mobil1 above. It does have ZDP but still may or may not be satisfactory for the slipper cam materials in the Lyc. It actually looks like the racing oil might compare best. A discussion with Mobil might help narrow the choices.

Each engine may be specific as to the additives needed, and engine developers can not test with every oil. If they only recommend one to keep warranty, then they legally have to supply that oil free. This is why (I believe) that new cars have free oil changes for a certain period. Not a bad marketing ploy either.

BTW - anyone heard of the chicken tax? It's why all pickup trucks are made in USA.
 
It seems to me that Doug Eves is the only one that is in a position to provide any real evidence in support of using auto oils. My personal opinion is that Ashless Dispersant aviation oils are designed to cope with the TEL ( lead ) in Avgas, first and foremost. When Mobil introduced its Mobil One full synthetic aviation oils some years ago, the problem was it was incompatible with the high lead in the fuel and formed a grey sludge in the sump.
So it seems that by changing to unleaded fuel, then it opens the way to use auto oil, but rather than the thin 0-30 used in modern high-revving watercooled engines for fuel economy with its additives that make wet clutches in motorcycles slip, an oil suited to high-performance aircooled engines ( Harleys spring to mind) which often have extra ZDPP ( zinc) necessary for things like flat tappet cams. I love avgas but it does leave deposits in the combustion chamber and contaminate the oil. A cleaner burning mogas should allow greater options on what oil to use, but we need testing. If it has been done, then there are a lot of interested people waiting to learn more.
 
When the Rocket flies again I will be running a test series with the intent of determining if EFI and careful ignition timing will allow unrestricted use of automotive pump gas. If this works and I am truely free from 100LL, then alternative oil will be the next subject of study. Interested in learning more about this.
 
..........with its additives that make wet clutches in motorcycles slip, an oil suited to high-performance aircooled engines ( Harleys spring to mind)

Nonono. There are not and have never been additives for wet clutches to slip more. Whoever wrote that "heard that from someone". Noone needs a clutch to slip more - oil is slick enough as it is in this application. As for Harleys, they've been roller motors since at least the 70s that I know of, probably earlier - they dont need ZDDP. For that matter, radial engines dont need ZDDP either because they've been roller cam since their inception. Its only the traditional flat motors that are the sliders - Lycs, Connies, Franklins etc....
 
OIL

Here is the test results from two different testing labs that came back with the same outcome for Aeroshell 15w50w aviation oil it was also wear tested showing it had very good wear protection .Now here is the kicker it has what you would call a trace of Zinc 1 and even a smaller trace of Moly <1.So the guys that say you need lots of zinc are just flat out wrong.You need lots of oil pressure and no air bubbles in the flow.You can not compress oil that is thick to thin yes as designed no.
FE<1 CR<1PB<1CU<1SN<1AL<1NI<1AG<1TI<1V<1
SI5 NA3 K5 MG<1 CA<1 BA<1
Phosphorus 1365
Zinc1
Molybdenum<1
Boron<
Viscosity 19 @100c
So now you have the facts to help find a replacement oil for your Lyco
but please don't run Diesel oil as it has the worst wear protection much lower than almost all car oil even when it has lots of zinc.
Bob
 
Nonono. There are not and have never been additives for wet clutches to slip more. Whoever wrote that "heard that from someone". Noone needs a clutch to slip more - oil is slick enough as it is in this application...

Not exactly relevant to this forum, but In 1990 I bought a brand new Honda CBR 1000 and as soon as I broke the engine in I added Slick 50 (buying into the hype), and immedietely noticed some strange clutch behavior. LOTS of slippage, which persisted for about 10,000 miles after that stuff was drained.
 
Here is the test results from two different testing labs that came back with the same outcome for Aeroshell 15w50w aviation oil it was also wear tested showing it had very good wear protection .Now here is the kicker it has what you would call a trace of Zinc 1 and even a smaller trace of Moly <1.So the guys that say you need lots of zinc are just flat out wrong.You need lots of oil pressure and no air bubbles in the flow.You can not compress oil that is thick to thin yes as designed no.
FE<1 CR<1PB<1CU<1SN<1AL<1NI<1AG<1TI<1V<1
SI5 NA3 K5 MG<1 CA<1 BA<1
Phosphorus 1365
Zinc1
Molybdenum<1
Boron<
Viscosity 19 @100c
So now you have the facts to help find a replacement oil for your Lyco
but please don't run Diesel oil as it has the worst wear protection much lower than almost all car oil even when it has lots of zinc.
Bob


LOL. Phosphorous and Zinc do the same thing, but you dont use both cause they dont like each other in oil. Whats that P number look like to you?

As far as Diesel oil being poor wear protection, how many million mile over the road 18 wheel tractors are on the road today? Anything over 5yrs my friend. And they are low speed high compression high heat engines with really big hot high spinning turbos that often NEVER get shut off except for an oil change. Not to mention all the Cat tractors and off road equipment of all types that gets abused and never get routine oil changes. Diesels all of them. With diesel oils.
 
Last edited:
Anti-wear

LOL. Phosphorous and Zinc do the same thing, but you dont use both cause they dont like each other in oil. Whats that P number look like to you?

Not quite. ZDP and ZDDP Are common anti-wear ingredients that are used in oil. They are zinc/phosphorous compounds. The 540ratblog shows similar amounts of zinc and phos in most gas/diesel oils, which indicates that these are the anti-wear components in these oils.

Since the aircraft oil shows just phosphorous in any significant amount, my guess is that TCP, which is effective at a higher temp is used instead for anti-wear in aircraft oils. See https://en.wikipedia.org/wiki/Antiwear_additive

BTW, I am an old guy and remember the no detergent/AD, straight mineral aircraft oil days. You would not want to go back. Let's hear it for chemistry!

Ron
 
600+ hours here running VR1 50w in the summer and VR1 20/50 in the winter.
10:1, o-320, no mogas, no issues. Seems to run better than the aviation oils I have used. No appreciable cost savings but it is much more widely available.
 
Leaving the Ashless Disperssant issue to the side, as I think everyone understands it's role and importance, the big threat with auto oil is the reduced high pressure anti-wear components. Namely ZDDP. By the 90's all auto engines were delivered with roller tappets instead of flat tappet lifters. The tree huggers then began to fight for ZDDP reduction due to it's environmental impact. The Feds complied by significantly reducing the limits of ZDDP in the oil specs as it really wasn't necessary with the roller tappets (high pressure anti-wear additives are mostly only required in the cam/lifter interface). Those with olders engines, using flat tappets, began to see a rapid increase in cam failure rates with the new oils. This topic is discussed actively on the web and you can do your own research. However, using modern spec'ed automotive oil in an engine with flat tappet lifters is literally begging for cam failure. The diesel oil specs allow for more ZDDP, but it is also being incrementally reduced.

Larry
 
Here's another perspective. I've been running Mobil 1 in every engine I've owned since the early '80s. Every one with sliding element valve trains. Never had any sort of cam or rocker issues on any and several of these engines had 200,000+ miles on them. Drove every single one really hard. This includes pushrod race engines revving to 8500 rpm with much higher spring pressures than stock.

As I said earlier, have a couple of Lyc customers who've used Mobil 1 too for many hundreds of hours collectively. No issues to date.
 
I recall that Delo 100 and Delvac 1240 motor oils are low ash formulations to reduce cylinder wear in ported 2 stroke (Detroit) diesel engines.
I have a couple drums of the Delvac 40W. I've used most of one on old cars & trucks. I think it would be a suitable 'emergency replacement' oil for an air cooled aircraft engine. I hope we never have such an 'emergency'.
I buy Philips X/C by the case ($55) at the local fuel distributor, it's about the same price as auto oil. You don't have to pay $9 a quart for it at the FBO unless you are happy to help them keep their 'heads above water'.
 
Here's another perspective. I've been running Mobil 1 in every engine I've owned since the early '80s. Every one with sliding element valve trains. Never had any sort of cam or rocker issues on any and several of these engines had 200,000+ miles on them. Drove every single one really hard. This includes pushrod race engines revving to 8500 rpm with much higher spring pressures than stock.

As I said earlier, have a couple of Lyc customers who've used Mobil 1 too for many hundreds of hours collectively. No issues to date.

The cast cams, with chilled iron followers are/were the most vulnerable. In support of your experience: Look at the Mobil 1 oil table I referenced. It shows zinc and phosphorus content in the oils for slipper cams. Racing oils have more of both. There is an industry test for this.

IIRC, There was a several year time gap (2-3) in the offering of oils until a new test standard addressed the slipper follower cams (early 80's?). The automotive need was short-lived as the EPA required a 100k mile durability for US engines and the cheap cam/followers disappeared from production. I think that was 1985.
 
Back
Top