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Newbie Owner Question: Oil Types

bill.hutchison

Well Known Member
It is amazing what one starts to learn when one has to.

Prior to owning an airplane, I simply put whatever oil the aircraft owner/operator specified in the airplane. Same with the flight school I teach at: use what they want.

Now that I have my own airplane, I'm trying to figure some things out.

My RV6a (ECI Titan 180hp / CS Prop) came from Texas. Last oil change the owner put in SAE 60, 20w50 oil in it. This is also what they run in the 180hp Lycomings in the 172s I typically teach in. They have some nice, warmer days there and fairly mild winters compared to VA/MD.

My PoH has a nice table in it showing recommended oils based on temps, and now that it's getting cooler here on the east coast, I'm generally going to be flying in average temps below 70F.

The table is recommending either MIL-L-6082 grade SAE 20 or - for Ashless Dispersant Grades - SAE 30 or 20w30 oil.

So...go ahead and switch to the lighter oil? Or stick with the 20w50 thats already in it and seems to be an all-season oil in similar engines?

I need to order some oil from Spruce and trying to decide what to buy.
 
Is the plane in a hangar?

If so, is the hangar heated? Or, do you have an engine preheater of some kind?

Do you expect to leave the plane outdoors sometimes, like overnight trips?
 
Is the plane in a hangar?

If so, is the hangar heated? Or, do you have an engine preheater of some kind?

Do you expect to leave the plane outdoors sometimes, like overnight trips?

Plane is hangared.

Hangar is not heated, and I do not as of yet have a pre-heater but it is something I have been giving consideration to.

It is likely that it will be outdoors occasionally on overnight trips.
 
In that case, my personal choice would be using the lighter weight or multi weight oils.
 
It is amazing what one starts to learn when one has to.

Prior to owning an airplane, I simply put whatever oil the aircraft owner/operator specified in the airplane. Same with the flight school I teach at: use what they want.

Now that I have my own airplane, I'm trying to figure some things out.

My RV6a (ECI Titan 180hp / CS Prop) came from Texas. Last oil change the owner put in SAE 60, 20w50 oil in it. This is also what they run in the 180hp Lycomings in the 172s I typically teach in. They have some nice, warmer days there and fairly mild winters compared to VA/MD.

My PoH has a nice table in it showing recommended oils based on temps, and now that it's getting cooler here on the east coast, I'm generally going to be flying in average temps below 70F.

The table is recommending either MIL-L-6082 grade SAE 20 or - for Ashless Dispersant Grades - SAE 30 or 20w30 oil.

So...go ahead and switch to the lighter oil? Or stick with the 20w50 thats already in it and seems to be an all-season oil in similar engines?

I need to order some oil from Spruce and trying to decide what to buy.

SAE 30 is thicker than 20W50 when cold, so that is worse. 20W30 is also a 20 wt oil when cold, so no improvement. I fly 20W50 year round, as do many others. 20W50 is 20 wt when cold and 50 wt when hot. A perfect compromise and why most fly with this blend. The additive packages that allow this viscosity range did not exist in the 50's and therefore why it is not recommended by Lyc. CHange over there is resisted agressively.

Larry
 
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I’m kind of a fan of Mike Busch at Savvy Aviation. He seems like a pretty smart guy. He has a really good (IMHO) review of aviation oils here: https://resources.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2011-01_all-about-oil.pdf

He’s kind of ambivalent about semi-synthetic multi-viscosity oil (eg...Aeroshell 15W40) partly because multi-vis oils don’t hang around in the cylinders as long, and partly (mostly?) because he perceives they interact badly with the lead in today’s av-gas (100LL). He likes multi-vis oil OK, but not a fan of synthetic in airplane applications). I say this as I am meeting my A&P tomorrow morning to change over to AeroShell 15W40 (this is Minnesota - it was 72 degrees today, but that’s not going to last...).

https://resources.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2011-01_all-about-oil.pdf
 
I’m kind of a fan of Mike Busch at Savvy Aviation. He seems like a pretty smart guy. He has a really good (IMHO) review of aviation oils here: https://resources.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2011-01_all-about-oil.pdf

He’s kind of ambivalent about semi-synthetic multi-viscosity oil (eg...Aeroshell 15W40) partly because multi-vis oils don’t hang around in the cylinders as long, and partly (mostly?) because he perceives they interact badly with the lead in today’s av-gas (100LL). He likes multi-vis oil OK, but not a fan of synthetic in airplane applications). I say this as I am meeting my A&P tomorrow morning to change over to AeroShell 15W40 (this is Minnesota - it was 72 degrees today, but that’s not going to last...).

https://resources.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2011-01_all-about-oil.pdf

Mike does not have a clue what he is talking about when it comes to synthetic oil and lead deposits. He is quoting his theory based on the problems that Mobil had with their aviation oils back in the late eighties. The synthetic base stocks used today by most oil companies start out as 100% crude oil. Synthetic oils that use 100% PAO base formulations like Mobil did years ago, did have some lead suspension issues, but that was years ago. If the synthetic based stocks that Shell uses caused any issues with lead suspension they would have stopped manufacturing it years ago. This is my opinion based on over 50 years of working with synthetic oils.
george
 
To the OP: Some oils come with the Lycoming LW-16702 anti-scuff/anti-wear additive. Aeroshell single weight "Plus" oils and their 15W-50 multi-weight oil come with it. The relatively new Phillips Aviation "Victory" series of single weight and multi-weight oils also have the Lycoming additive.

And then there is the choice to add CamGuard. Note that CamGuard is not the same as the Lycoming LW-16702 additive.

Highly recommend preheating below 32* F. Lycoming's recommendations on preheating:


Thanks for the information - was doing some research in parallel with this thread and came up similarly.

Interestingly, although CamGuard is not the same as the additive, CamGuard says (on the AircraftSpruce website) that since the Phillips Victory already has an anti-wear additive, the CamGuard effectiveness may not be as good.
 
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