Millerol – non detergent monograde (SAE30, SAE40, SAE50): this range is suited to veteran and vintage cars, ie. pre-WW2, which had very primitive oil filtration systems and used non-detergent oils. This oil contains anti-wear and anti-corrosion additives, but does not contain detergents. A lower viscosity oil would be needed in the winter, such as Millerol 30 and a higher viscosity in the summer, such as Millerol 40. The gearboxes also use the same type of oil, usually a higher viscosity than the engine, eg. Millerol 50. The oil needs to be changed regularly due to the lack of detergent content.