-AV8R-
Registered User
Connecticut
So, my new (to me) Legend cub was delivered to CT from TX last week. After a solid week waiting out blustery IFR conditions, I'm dying to get my first solo flight in it, and the weather has finally cleared and the wind died down. Its a perfect day save for one thing. We had a dramatic temperature drop yesterday, with snow, and its below freezing today. My lycoming O-233 was delivered with 100W oil, and the book calls for 15W-20W oil in colder temperatures. This started me wondering about several questions.
- My Hangar usually doesn't go below 40 degrees, so its probably fine to start the engine, but I don't know. I don't have a pre-heater, and wouldn't even use it above freezing temps anyway. I would normally do the oil change, throw some 15W-50 in it and be done, but it got me wondering. What difference does it make if the engine operating temp and oil temps are within acceptable range anyway? Is it just at the engine start that it matters? Because in spring and fall 50-70 degree temp range on the ground you can easily find below freezing temps at altitude and operate there for hours. even with a summer weight oil the engine may be operated in below freezing temps at altitude, so when is it the recommended oil viscosity REALLY matters? at start. or in the air? I want to go fly, but do not want to damage my engine. Its got summer weight oil in it, and I can start it near 40 degrees, by starting it very soon after pulling it out of the hangar, but from the minute I leave the hangar its in freezing temps.
- My Hangar usually doesn't go below 40 degrees, so its probably fine to start the engine, but I don't know. I don't have a pre-heater, and wouldn't even use it above freezing temps anyway. I would normally do the oil change, throw some 15W-50 in it and be done, but it got me wondering. What difference does it make if the engine operating temp and oil temps are within acceptable range anyway? Is it just at the engine start that it matters? Because in spring and fall 50-70 degree temp range on the ground you can easily find below freezing temps at altitude and operate there for hours. even with a summer weight oil the engine may be operated in below freezing temps at altitude, so when is it the recommended oil viscosity REALLY matters? at start. or in the air? I want to go fly, but do not want to damage my engine. Its got summer weight oil in it, and I can start it near 40 degrees, by starting it very soon after pulling it out of the hangar, but from the minute I leave the hangar its in freezing temps.
Last edited: