Why the difference? Easy. The leak's getting worse! What could it be? Oil cap loose? Valve cover gaskets, oil pan gasket, Front/rear crankshaft seal, etc. Have it fixed before the underside of the car is covered in oil from bumper to bumper. By the way, are you sure it's oil that's leaking? Could it be ATF? I'm sure everyone here would like to help, but could you provide a little more info?