There should be two types of answers a) in case one buys the oil or b) one has already bought the oil.\r• Check all the international standards and specifications.\r• Check the OEM specifications in general. IF there is any confusion please ask a professional.\r• Check if the base stock oil is synthetic or mineral.\r• Check that the right viscosity is added.\rThe second part of the answer can be checked if you already have used the oil then:\r• Check if the oil inside the vehicle or application decreased significantly, this could also happen if the wrong oil is used. \r• Check if the viscosity changed this could also be an indication that the oil used is not compatible with the application. \r• Also, check if the sound of the engine increased, If the sound increased or vibration increased more than normal when the engine is turned on it means that the moving parts are behaving uncommonly and the moving parts are in more contact with one another. Then try to check if you added the right oil. If so the reader can deduce that the lubricant oil for the engine added is of low quality.\r• Also, check with the main Motul distributer in Egypt.