Use our high grade quality 20W40 Engine Oil 5 litre which are multi viscosity motor oils and they have the 20 weight viscosity in cold temperature. The 40 indicate that they have comparable viscosity during hot temperature. Also, they are used for different purposes such as lubricant in wet type transformers, diffusion pumps and oil-filled heaters, etc. The 20W40 Engine Oil 5 litre oils are featured by good heat transfer property, high volatility, extreme temperature stability and excellent electrical strength.