A fresh motor oil stain from concrete is easier to remove than an old stain. Squirt some liquid dish detergent (preferably one designed for cutting grease) onto the stain. Add water. Be sure to wet down the area surrounding the stain as well to prevent oil from spreading during the cleaning process and causing a secondary stain. Scrub the stain vigorously with a nylon scrub brush (not a wire brush which can erode or scratch the concrete), adding enough water to make a rich soapy lather. Rinse with clean water. The soap will emulsify the oil and lift it out of the concrete, but it may take several attempts to completely remove all of the oil. When rinsing the area, it is more environmentally responsible to blot the area with a towel to remove the soapy water, since rinsing the mixture with a hose will allow the motor oil in the water to seep into the ecosystem or sewer system. Another way to remove motor oil from concrete is to spread a thick layer of cat litter over the grease to absorb the excess motor oil on the surface. Allow the litter to sit for a day or two, then sweep it away. Pour dry concrete over the dried grease spot. Allow the concrete to sit for a day or two, then sweep away the dirty concrete. Be sure to gather both the cat litter and the dirty concrete in a bag and dispose of it properly so the motor oil doesn't get into the ecosystem or sewer system. Contact your local waste collection service for more information.