what oil

"What oil" refers to the type of motor oil that is recommended for a specific car. The type of oil that a car takes depends on factors such as the vehicle, the model year, and the engine type. Manufacturers recommend motor oil based on viscosity grade and performance specification, which can be found in the vehicle owners manual. The Society of Automotive Engineers (SAE) has developed a grading system for engine oil, with 5W-30 engine oil being a common grade. It is important to use the right oil in the engine, as it acts as a lubricant, coats metal parts to prevent rust and oxidization, and reduces friction between moving parts. Using the wrong oil could result in sudden and expensive repairs. To find the right oil and oil filter for a car, one can use an oil selector tool provided by companies such as Pennzoil, Mobil, and Castrol.