1. Viscosity: Diesel engines generally operate at higher temperatures and pressures compared to petrol engines. Therefore, diesel engine oils have a higher viscosity to provide sufficient lubrication and protection for the engine's moving parts under these demanding conditions. Petrol engine oils, on the other hand, are typically thinner (lower viscosity) to reduce friction and improve fuel efficiency.
2. Additives: Diesel engine oils contain a higher concentration of certain additives compared to petrol engine oils. These additives help to combat the effects of soot, acids, and other contaminants produced by diesel fuel. They include detergents, dispersants, anti-wear agents, and antioxidants, among others. These additives are designed to maintain engine cleanliness, minimize deposit formation, and extend oil drain intervals.
3. Base Oil: Diesel engine oils are typically formulated with a higher percentage of synthetic base oils compared to petrol engine oils. Synthetic oils offer superior stability, resistance to thermal breakdown, and improved low-temperature performance. This is particularly important for diesel engines, which often operate under heavy load and experience wide temperature variations.
4. Performance Standards: Diesel engine oils must meet specific performance standards and industry specifications that are different from those for petrol engine oils. These standards are established by organizations like the American Petroleum Institute (API) and the European Automobile Manufacturers Association (ACEA). Diesel engine oils carry designations that indicate their suitability for various types of diesel engines and emissions control systems.
5. Drain Intervals: Drain intervals for diesel engine oils are typically longer compared to petrol engine oils. This is due to the higher concentration of additives and the fact that diesel engines generally produce less soot and contaminants than petrol engines. However, it's essential to follow the manufacturer's recommended drain intervals based on the specific engine and operating conditions.
It's important to use the correct type of oil for your vehicle as recommended by the manufacturer. Using the wrong oil can compromise the engine's performance, reduce its lifespan, and even cause damage. Refer to your vehicle's owner's manual or consult with a qualified mechanic to ensure you are using the appropriate oil for your diesel or petrol car.
