To find the right oil for your car, you can use an oil finder tool provided by various companies such as Mobil, Castrol, Halfords, AutoZone, Total UK, and Opie Oils. These tools require you to enter your car details, such as make, model, and year, and will provide you with the correct specification and amount of engine oil for servicing your engine. You can also find the recommended car engine oil grade/viscosity and specification within your vehicles handbook. It is important to use the oil that your engine was designed to take to maintain the efficiency, lifespan, and performance of your engine.