Types of Lubricant

Car lubricants play four major roles – they control friction and wear in the engine, they protect the engine from rusting, they cool the pistons, and they protect the engine oil stored in the sump from combustion gases.
SAE 15W/40 was developed for four-stroke petrol and diesel engines with or without turbos; it can be used in commercial vehicles, work machines or industrial units as well as passenger vehicles, making it the ideal motor oil for a mixed fleet of vehicles.
10w30 is a multi-grade engine oil ideal for heavy-load engines because of its ability to withstand hot temperatures for a long time without compromising the performance of the engine. This engine oil has a viscosity grade of 10 in low temperatures and 30 in high temperatures.
A SAE 20W-50 motor oil is typically used in older vehicles or in particularly warm climates. Castrol GTX 20W-50 has been specially formulated to help extend the life of your engine by keeping it free from sludge, even when operating in extremely high temperatures.
SAE 15W40 can be used with complete success in over-the-road diesel trucks, off-highway diesel equipment, farm tractors, and passenger cars and light trucks with diesel, turbo-charged diesel engines, or gasoline engines and is backward compatible with previous API Oil Categories.
These oils coat moving gears and parts with a film of oil that protects the parts from friction that over time would destroy the quality of these parts. Oil-based lubricants are the most widely used and common in the industrial lubricant types as they are used in almost every single road vehicle.