Euro Tech 20W50 API SF

It seems like you're providing information about a specific type of engine oil. "PETROL & CNG ENGINE OIL, 20W50 API SF, Brand: Euro Tech 20W50 API SF" appears to be the product name, specifications, and brand of an engine oil.

PETROL & CNG ENGINE OIL: This indicates that the engine oil is suitable for both petrol (gasoline) and compressed natural gas (CNG) engines.
20W50: The "20W50" refers to the viscosity grade of the engine oil. It is a multi-viscosity oil, meaning it has different viscosities depending on the temperature. The "20W" indicates the oil's flow characteristics in cold temperatures (W stands for winter), and the "50" indicates its viscosity at higher temperatures. This type of oil is often used in older or high-mileage engines.
API SF: The API (American Petroleum Institute) designation "SF" represents the service classification of the engine oil. The "SF" classification is an older specification that denotes the oil's performance and suitability for certain types of engines. It's worth noting that "SF" is an older specification and may not meet the requirements of more modern engines.
Brand: Euro Tech: This is the brand name of the engine oil, indicating the manufacturer or company that produces it.
Please note that my knowledge is based on information available up until September 2021. It's possible that there have been updates or changes in engine oil specifications or classifications since then. It's always a good idea to refer to the latest guidelines and recommendations from your vehicle's manufacturer or trusted sources when selecting engine oil for your vehicle.