What is the oil grade for Audi A3?

[LeAna]

Audi A3 uses SN-grade engine oil with the specification of 5W-40. Definition of engine oil: Engine oil, also known as motor lubricant, serves multiple functions including lubrication and friction reduction, auxiliary cooling, sealing against leaks, rust and corrosion prevention, as well as shock absorption. It is often referred to as the 'blood' of a car. Engine oil consists of base oil and additives. Base oil is the primary component, determining the fundamental properties of the lubricant, while additives compensate for and enhance the performance of the base oil, providing additional characteristics. Additives are a crucial part of engine oil. Classification of engine oil grades: SAE viscosity classification: According to the viscosity grade classification, lubricants are divided into three types: high-temperature types for summer, low-temperature types for winter, and all-season types suitable for both winter and summer. High-temperature types for summer include 20, 30, 40, and 50, where a higher number indicates greater viscosity and suitability for higher temperatures. Low-temperature types for winter include 0W, 5W, 10W, 15W, 20W, and 25W, where the 'W' stands for Winter, and a smaller number before 'W' indicates lower viscosity and better low-temperature fluidity, making it suitable for lower temperatures. All-season types include 5W-20, 5W-30, 5W-40, 5W-50, 10W-20, 10W-30, 10W-40, and 10W-50, where a smaller number before 'W' indicates suitability for lower temperatures, and a larger number after the hyphen indicates suitability for higher temperatures. API engine oil quality classification: API engine oils are divided into two categories: those starting with 'S' are suitable for gasoline engines, while those starting with 'C' are suitable for both gasoline and diesel engines. For 'S' category oils (SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN), each subsequent letter represents a higher grade than the previous one (e.g., SN is higher than SM). Similarly, for 'C' category oils (CA, CB, CC, CD, CE, CF), the further the letter is in the alphabet, the higher the oil grade.