Oil

[Mtns2Skies]

It’s called oil dilution and most of the WWII airplanes had it, although I have not seen any today with it still installed.

Beech 18 on floats I flew had it installed.

 

[flyingbrit]

Why do people talk about the weight of oil? The correct term is viscosity. I figure it's sheer laziness; one syllable is easier than four. And by the way, the "W" in 20W-50 does not stand for "weight"; it stands for "winter". Now get off my lawn!

 

[Sac Arrow]

Why do people talk about the weight of oil? The correct term is viscosity. I figure it's sheer laziness; one syllable is easier than four. And by the way, the "W" in 20W-50 does not stand for "weight"; it stands for "winter". Now get off my lawn!

It's because six pounds per gallon is important when calculating W&B.

 

[Dan Thomas]

And by the way, the "W" in 20W-50 does not stand for "weight"; it stands for "winter".

That's only true for multigrades. The textbooks, and the manufacturers, say this:





From https://www.overlakeoil.com/aviation/aeroshell/

Mike Busch outlines it this way:



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

 

[flyingbrit]

It's because six pounds per gallon is important when calculating W&B.

If it's that important you might want to use the correct number. Six pounds/gal is typically used for gasoline. Oil is typically figured at 7.5lbs/gal or rounded up to 8:

https://www.flight-mechanic.com/sta...pecific weight for,Lubricating oil 7.5 lb/gal

 

[Huckster79]

Summer 100w and winter 20/50

 

[Sac Arrow]

If it's that important you might want to use the correct number. Six pounds/gal is typically used for gasoline. Oil is typically figured at 7.5lbs/gal or rounded up to 8:

https://www.flight-mechanic.com/standard-weights-used-for-aircraft-weight-and-balance/#:~:text=Unless the specific weight for,Lubricating oil 7.5 lb/gal

But I use a light weight oil!