Scudrunners

My Mechanic convinced me to run 100 weight oil in my plane over the Phillips 20w50 we’ve been running.

Long and short if you’re not flying it that much and parking it for the winter it’s best to have a thicker coat on the engine parts to help prevent corrosion etc.

Thoughts?

Scudrunner wrote: ↑

Wed Jul 26, 2023 1:17 am

My Mechanic convinced me to run 100 weight oil in my plane over the Phillips 20w50 we’ve been running.

Long and short if you’re not flying it that much and parking it for the winter it’s best to have a thicker coat on the engine parts to help prevent corrosion etc.

Thoughts?

I run Philips 25W50 in my Grumman AA1B and W25-60 in my Nanchang. Never had any issues but I try to get both in the air at least once every 2 weeks, especially the AA1B.

IMHO multigrade oil is for severe cold only. It doesn’t make amy sense in warm temps.

I run W100 in the winter and W120 in the summer. If you’re going to park an engine, W120 and 10% Camguard is the answer.

Drain the hot oil yourself sometime. Multi-vis will piss out like water. It does a terrible job when the oil gets over 200F.

https://www.avweb.com/ownership/which-oil-should-i-use/

Good write up in here on Avweb.

It’s funny when I was bombing around the north and such in piston bangers I never recall thinking about type of oil let alone my ame telling me the why this or that grade.

Even during ground school I don’t believe it came up. Other than check your oil and make sure you keep some extra on bird to add on your cross country trips.

Now those planes where being flown daily, heck I recall pounding out 50 hours in 5 days a number of times.

As a new owner of an aircraft even with my families background with airplanes I didn’t give it much thought.

Oil looks good and is at its happy spot giver bud!

Good article.

When I lived in Canada and it got cold in the winter I ran 15w50 in the winter. Necessary evil, not just for start but to avoid congealing in oil cooler. Good to -40, your choice C or F. Expensive and attacked the seals of the aircraft though. Ok if you don’t mind oil leaks. Not a fan of that blue bottle cat piss. It’s cheap and wet I guess. Harv runs it in Steinbach so it must kind of work.

In the summer I would run W100 in Canada. Multi-grade is completely unnecessary when it’s warm and my experience is that it’s much thinner when hot. Runs out like water.

Now that I live somewhere that never gets cold I run W100 in the winter and W120 in the summer as per Lycoming’s recommendations for those temperatures.



W100 and W120 doesn’t attack my engine seals, cheap, stays thick at high temps which results in higher oil pressures and better prop control. RPM doesn't wander when the oil temp climbs and the pressure drops.

Biggest problem private piston airplanes have is internal corrosion. They never make flight time TBO and the thicker straight grade oil - esp with Camguard- really helps with this.

W120 and 10% Camguard is a superb inhibiting oil. For any aircraft that isn’t flown in the winter, it is the best choice.