Best Oil for Continental O300-D 6 Cyl

[erm]

I have a 1965 Cessna 172F with a Continental O300-D

A lot has changed since that engine was designed and the manual written.

I did some initial reading and settled on Exxon Elite oil rather than Aeroshell.

However, with all the specialty formulated oils out there today, synthetics, etc. I wondered if there were oils that might be as good and cheaper or better and the same price.

For instance, I use Mobile 1 Fully Synthetic V-Twin 20X-50 for my air cooled motorcycle engines. This oil might be superior to Exxon Elite.

I am hoping to get some good advice from an oil expert.

Problems with the Continental O300-D engine in general include lead fouling from 100LL resulting in stuck valves, oil consumption (most use about a quart every 3 to 6 hours), some run hot during climb at full power, etc.

Since these engines require 8 quarts of oil, burn oil (as about any air cooled engine running WOT will do), and oil is replaced every 50 hours (not to mention basically a full change between as a result replacing 1 quart every 4 to 6 hours) I would like to reduce the operating cost by finding a lower cost oil but not at the expense of the engine.

Thanks for any advice

 

[2cool]

I believe that you must use oils approved by the FAA as well as the engine manufacturer. The operating parameters for aircraft are not the same as for road vehicles, and the chemistry is different in the gasoline. For no other reason, I'd stick with aircraft rated oils because while the catchphrase "failure is not an option" has become popular; at 8000 feet it's how it had better be.

 

[Robster]

Do NOT run anything other than oil approved for aviation applications!-aviation oil has very different chemistry than automotive oil.

The oil in a piston aircraft engine can have a profound effect on it's operation. . .for instance, check this article: http://www.avweb.com/news/news/182891-1.html . . . .that little experiment didn't work out so well for Mobil or the unfortunate ones that had engine failures as a result. . .and that oil WAS approved. I use this example to illustrate how oil can adversely impact the operation of your aircraft engine.

Considering the overall cost of operating an aircraft these days, it doesn't make sense to go "cheap" on the oil. . .just my two cents. . .

 

[Johnny]

I would use either AeroShell 15W-50 or the Phillips X/C 20W-50 oil in your Continental. Not that it makes any difference, but it cam from Cessna with the Phillips in it.

 

[edhackett]

Robster mentioned the chemistry differences.

Aviation oils contain basically an ashless dispersant, anti-foam, and corrosion inhibitors.

Automotive oils contain ash forming detergents and anti-wear additives, such as ZDDP. In an aircraft engine those will increase plug fouling, valve sticking, and the possibility of detonation.

Do not use any oil other than one specifically formulated for air cooled aircraft engines.

I've flown in a 172 of that vintage. That O300 is one smooth motor. Take good care of it

Ed

 

[Robster]

. . .and besides, AeroShell 15-50 is cheaper than the Mobil 1 V-Twin motorcycle oil you mentioned. . .at least in Central PA anyway.

For what it's worth, I've been using the AeroShell stuff for over 20 years in various aircraft, with never an oil-related problem--it just works. Although I've used the semi-syn AeroShell almost exclusively, lots of airplanes are run to TBO using the mineral stuff.

You mentioned Exxon Elite. . .I DID try that for a year or so and it too worked fine. . .the one difference that I noticed with the Exxon is that the Lycomings seemed to blow more of that out than when using the AeroShell. . .I was constantly cleaning the oil off the cowlings.

 

[Cujet]

I use aeroshell 15-50ss with excellent results. It does a great job reducing internal corrosion. A neighbor aircraft of the same type uses conventional oils. He was shocked to find corrosion on his connecting rods. Same engine, both low time, same hangar. Different oil. However, his engine did not show excess signs of wear.

 

[Cujet]

What I meant to say is that both engines show similar wear. The conventional oil does not seem to wear more rapidly.

However, the synthetic is certainly cleaner.

 

[merdog]

The Phillips XC has been around for years and the aero shell is an awesome oil also. Either one will be way with in specs for your conti. If you are worried about corrosion change your oil a little more often to get the junk out sooner. See you out there. Rick

 

[Cujet]

Originally Posted By: merdog
The Phillips XC has been around for years and the aero shell is an awesome oil also. Either one will be way with in specs for your conti. If you are worried about corrosion change your oil a little more often to get the junk out sooner. See you out there. Rick


Also, Camguard is a product that claims to sharply reduce internal engine corrosion. I now run it in my aircraft and in my company aircraft. Clearly, it works well in bench tests (on a sheet metal test strip).

The product makes no claims, other than it reduces corrosion. I spoke with the company at Sun N Fun and they claim that Aeroshell 15-50 already has the same additive in it, as, you guessed it, a corrosion inhibitor. It's a fairly new product and time will tell.

 

[Edward Kollin]

Originally Posted By: Cujet
Originally Posted By: merdog
The Phillips XC has been around for years and the aero shell is an awesome oil also. Either one will be way with in specs for your conti. If you are worried about corrosion change your oil a little more often to get the junk out sooner. See you out there. Rick


Also, Camguard is a product that claims to sharply reduce internal engine corrosion. I now run it in my aircraft and in my company aircraft. Clearly, it works well in bench tests (on a sheet metal test strip).

The product makes no claims, other than it reduces corrosion. I spoke with the company at Sun N Fun and they claim that Aeroshell 15-50 already has the same additive in it, as, you guessed it, a corrosion inhibitor. It's a fairly new product and time will tell.



We make three additional claims for Camguard besides having 5 times the corrosion protection of the Aeroshell 15W-50 or Exxon Elite (due to having 25 times the level of rust and soft metal corrosion inhibitors). The Aeroshell 15W-50 has 0.05% of a partial ester rust inhibitor. It is NOT the same type or concentration as that found in Camguard. Phillips could not believe I could use such a high concentration of rust inhibitor with causing other problems. They were impressed.

Camguard dramatically reduces wear. We observe a reduction in wear metals, iron, nickel, and chrome an average of 35% in oil analysis of aircraft averaged over the past 10 years. It actually has a more effective anti-wear (and anti-scuff) package than the ZDDP in auto oils.

Camguard is the only aircraft lubricant that has deposit control additives. They virtually stop the formation of all deposits (varnish, carbon and sludge)from forming in the engine, The engineers at Lycoming and Continental could not believe that aircraft engines could remain so clean as our certification engine.

Camguard also conditions seals to stop weeping due to age or other oils additives.

Ed

 

[Cujet]

Hi Edward. I stand corrected. I simply repeated what I heard at SnF. This forum won't allow me to edit my previous post. So, please accept this correction.

Just an FYI, I am currently performing an annual inspection on my personal aircraft, a thunder Cardinal RG (ha ha). I pulled the left mag, as I do every year to check the impulse coupling and the crankshaft gear. Plus, of course, all the spark plugs. In years past, I would see tiny specs of surface rust on the impulse coupling, not this year. Nor do I have any corrosion on the gears, the cylinders or any parts that I can see.

Our Experimental Extra 300L is also in annual right now. The engine has a whopping 1.5 hours flight time since overhauled and installed last October. No corrosion there either. This engine has been replaced twice (in 200 hours) due to other reasons, and during each disassembly, we always found corrosion on the cylinder bores, camshaft (requiring replacement) and connecting rods. I will make sure to bore scope the camshaft, but so far, no corrosion noted.

Chris

 

[car54]

Camguard sounds like a miracle in a bottle. Does it cure the common cold, or come with a kitchen sink? =)

I'll have to give it a try sometime.

 

[Edward Kollin]

Originally Posted By: car54
Camguard sounds like a miracle in a bottle. Does it cure the common cold, or come with a kitchen sink? =)

I'll have to give it a try sometime.


Camguard is conceptually the additive package that I formulated for Exxon for the Elite. It proved to be too expensive. No Miracles.

Ed

 

[Mr_Joe]

For me it's Aeroshell 100+ in the Summer & Aeroshell 15W-50 in the Winter(pre-heat also).

 

[JustinC25]

The 172 my dad flies uses Aeroshell 15w50 (they also pre-heat in the winter) but that has a Lycoming O-320 as it is a 1973 172M.

 

[SEMI_287]

Aeroshell 15w50 in my Arrow, Lycoming IO-360-C1C6.