What do you do with unused/partial cans of oil?

[ModMech]

I use it, even mix brands, in any gas engine that gets used sparingly (pressure washer), but gets an oil change every year any way. If it's an odd weight I cannot use, it will accelerate the burn pile on a wet day

 

[farmboy65]

In the early 70's, we dumped waste oil on our gravel road, *sparingly and infrequently*, to keep-down the dust from passing cars. It was only a couple gallons spread over maybe a 100' stretch of road. It did make a difference. Ok, not a great idea today...we take our waste/unused oil to almost anyplace that does oil changes, and they will gladly recycle it with their waste oil.
Don't want to make the trip? Dip a rag, and wipe-down garden and hand tools, or anything else that's prone to rust. For example, when we finished plowing, we would 'paint' the shares and moldboards of the plow with grease before rust set-in on the scoured, bare metal. (got any 'waste grease'?, lol)
Fill an oil can and give every hinge a couple drops - including car doors.

 

[RalphVa]

If I'm a little bit short in filling up a crankcase, I use little bits of other oil.

Ralph

 

[pigpen60]

dump clean (unused) oil in fuel tank on non emission diesels.

 

[Parkanzky]

A few of my cars use very specific (and therefore fairly expensive) oil. For those, any extra goes on the shelf in the solvent cabinet and is used toward the next oil change.

For the more "normal" oils, I don't mind mixing grades or viscosities in my less precious vehicles. My pickup truck has the 6.0L GM gasser motor and I just did an oil change. It takes six quarts. So I bought a 5 qt. jug, poured that in, then made up the other quart with odds and ends from the solvent cabinet. That means it got a bit of high-dollar synthetic motorcycle oil and also a cheap bottle of lawnmower oil that has been on my shelf since my father passed away (and was probably on his shelf for 20 years before that!).

Other than a couple gallons of marine 2-stroke oil, I don't have much surplus oil right now.

 

[Dr_Zinj]

I only use one can of each type at a time. I go through 30W fairly often, so it never sits more than 3-6 mo unfinished. I do have a bottle of brake fluid that's been open for a couple of years that I occasionally need to top off the truck or car with. It's probably good for another few years before I reach the bottom.

 

[Parkanzky]

I only use one can of each type at a time. I go through 30W fairly often, so it never sits more than 3-6 mo unfinished. I do have a bottle of brake fluid that's been open for a couple of years that I occasionally need to top off the truck or car with. It's probably good for another few years before I reach the bottom.

Brake fluid is a different story. It is fairly hygroscopic (absorbs and retains water). Engine oil is not hygroscopic, and even if it were you'd boil off the excess moisture the first time you get the engine to operating temperature. Your brake system isn't like that, so you get decreased brake performance (mostly poor pedal feel) and risk corrosion in your brake system when you use wet fluid.

I keep the unused portion of the can from my most recent brake fluid flush on the shelf to top off in an emergency, but I'd never use old, opened, brake fluid in something I cared about.

 

[Bill41]

Brake fluid is a different story. It is fairly hygroscopic (absorbs and retains water). Engine oil is not hygroscopic, and even if it were you'd boil off the excess moisture the first time you get the engine to operating temperature. Your brake system isn't like that, so you get decreased brake performance (mostly poor pedal feel) and risk corrosion in your brake system when you use wet fluid.

I keep the unused portion of the can from my most recent brake fluid flush on the shelf to top off in an emergency, but I'd never use old, opened, brake fluid in something I cared about.

I use brake fluid on rubber hoses and rubber parts.

 

[Rabenfels]

use 5 gal plastic bucket 3/4 filled with sand / very fine gravel- pour in any left over oil until lightly wet - stick anything that needs light oil coating for protection/rust proofing into the sand. Nice for shovels, spades, hoes, mower blades etc. - garden tools - I leave them stuck in there until I need them. Come out clean and oily ...

 

[sdef]

use 5 gal plastic bucket 3/4 filled with sand / very fine gravel- pour in any left over oil until lightly wet - stick anything that needs light oil coating for protection/rust proofing into the sand. Nice for shovels, spades, hoes, mower blades etc. - garden tools - I leave them stuck in there until I need them. Come out clean and oily ...

I think this is the best idea I have see on this post.