Make a clean sweep of it
You work hard at making your house look attractive. So why settle for the “permanent” grease or oil spot on your concrete driveway? Get rid of it by pouring mineral spirits or paint thinner on the dirty area. Make sure it covers thoroughly. Then take a bag of of cat litter, sand or large box of baking soda (even corn meal will work – you just want something dry and absorbent) and spread it on the top of the spot. Leave it there for 12 hours or so and then sweep it up. The oil spot should be “gone with the litter”. Get up the final traces of the mineral spirits with warm water, regular detergent, and a mop. You can us this method with dry cement, too, but in that case, let is sit for a couple of days before sweeping it up.
Better safe then scar-y
If your not sure what surface material your’re dealing with, it’s best to play it safe. Many commercial products are available for cleaning concrete, blacktop, and various types of patio surfaces. These can be bought at hardware and some paint stores, and should tell you right on the bottle if they can clean your surface without scarring it.