How to Clean Used Motor Oil

by Aram Khayatpour
by Robert Couse-Baker

For many do-it-yourselfers, changing their car's motor oil is a regular task. However, most don't realize that they can recycle this oil themselves and use if for future oil changes. By using a short length of cotton rope as a filter, you can change quarts of used oil into fresh oil in your own garage in a matter of weeks.

Step 1

Cut the 2x4 to be the same height as one of the gallon bottles.

Step 2

Cut two 10x10 squares out of the wood sheet.

Step 3

Screw the two square boards onto the ends of the 2x4. The end result should be a stand with a flat bottom and a flat top that is about as tall as one of the bottles.

Step 4

Cut a piece of 2x4 that is 6 inches longer than the height of the two bottles combined.

Step 5

Cut a 6x6 and a 12x12 square out of the wood sheet.

Step 6

Screw the two squares you just cut onto the ends of the 2x4. The end result should be a tall stand with a large flat base and a smaller flat top.

Step 7

Place the smaller stand in an area where it can be left undisturbed for weeks.

Step 8

Put one of the bottles on top of this stand and place the other one on the ground right next to the stand.

Step 9

Fill the top bottle with used motor oil.

Step 10

Place one end of the cotton rope all the way down to the bottom of the used motor oil bottle and the other end as far down to the bottom of the other bottle as it will go.

Step 11

Check to make sure that the rope is not touching the edge of either bottle opening. If it is touching, move the bottles closer to each other (or farther away if needed) to change the arch of the rope until it is no longer touching the bottles' edges.

Step 12

Place the taller stand near the bottles and drape the large plastic sheet over it. Make sure that the sheet is not making any contact with the rope and is long enough to touch the floor. This sheet needs to block any dirt or dust from getting into the clean bottle, so make sure the inside is clean and is blocking off the bottles from the surrounding environment.

Wait a few weeks for the oil to move to the lower bottle; then add 1 quart of new motor oil for every 3 quarts of recycled.


  • Using a clear plastic sheet will help you see what is going on without having to disturb the filtering oil.


  • Take the remaining oil in the used oil bottle to a local auto repair shop to be recycled. Disposing of this fluid yourself or pouring it down the drain is hazardous to the environment and illegal.

Items you will need

  • 3.5 feet of cotton rope
  • A wooden 2x4 at least 48 inches long
  • A wooden board big enough to cut two 10x10, one 6x6, and one 12x12 square
  • Screws
  • Power drill
  • Two 1-gallon glass bottles
  • New motor oil
  • Used motor oil
  • Large plastic sheet

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