With a boat, and multiple cars,
I am faaaar too lazy to keep bringing them all in to some shop for constant oil changes.
And its really hard to put a boat up on a car lift to change its oil!
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Moeller makes this thing called a fluid extractor.
Apparently high end auto dealers use things similar.
https://www.moellermarine.com/produc...id-extractors/
It pulls oil from the bottom of the case through the dipstick, without ANY effort or slime.
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Instructions:
1. Mix a gin and tonic with a bit of ice.
2. Put on a nice clean white button-down, collared shirt, and khaki pants.
Lightly starched and neatly pressed, if you want to make a fashion statement.
Then tell your wife you are going out dressed this way to change oil.
3. Run the extractor's small tube down your dipstick
4. Hand pump the extractor lever a few times to produce a vacuum
5. Walk away while it slurps oil out of the engine over the next 5 minutes,
6. Have the gin and tonic. (Campari and ice may also be used).
7. Return used oil to autozone and buy replacement
9. Refill vehicles.
10. Save large oil containers for next time.
Yes, would work perfectly well on an airplane too....
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So maybe once or twice a year
I line up the fleet and change them all in a few minutes,
WITHOUT playing "oil-change round robin" with each car.
The cars' oil filters don't seem to get really dirty if serviced reasonably well.
So I change the filters maybe once every two years or so, when I feel guilty.
Simple, quick and clean