AUTO STAR 15W40 API CF-4

It looks like you're mentioning a specific type of diesel engine oil, specifically a 15W40 viscosity grade with API CF-4 specification, and the brand is "AUTO STAR." Diesel Engine Oils (DEO) are lubricants designed to be used in diesel engines to reduce friction, protect against wear, and provide cooling to the engine components. The viscosity grade (15W40) indicates the oil's flow characteristics at different temperatures.

The API CF-4 specification refers to a set of performance requirements established by the American Petroleum Institute (API) for diesel engine oils. CF-4 oils are designed for use in high-speed, four-stroke diesel engines and are formulated to provide good performance in terms of detergency, wear protection, and resistance to oxidation.

As for the brand "AUTO STAR," it appears to be the manufacturer or distributor of this particular diesel engine oil. It's important to note that the quality and performance of engine oils can vary between different brands, so it's advisable to ensure that the brand you're using meets the necessary industry standards and is recommended for your specific engine type.

When choosing engine oil, it's crucial to follow the manufacturer's recommendations and specifications outlined in your vehicle's owner's manual. Using the correct type and grade of oil is essential for ensuring optimal engine performance and longevity. If you have any specific questions about diesel engine oils or their usage, feel free to ask!