What does A3B4 on engine oil mean?
2 Answers
Engine oil labeled A3B4 refers to a dual-purpose lubricant suitable for both gasoline engines and light-duty diesel engines. A3B4 is a testing and certification standard for automotive lubricants established by the European automobile manufacturing industry. In practical use, it ensures the oil maintains its original viscosity grade to guarantee lubrication performance: 1. Gasoline engine lubricants are classified into five quality grades: (1) A1: Fuel-efficient, low viscosity, equivalent to API-SJ grade (semi-synthetic and full synthetic). (2) A2: Main product range, equivalent to API-SG and SF grades (mineral oil and semi-synthetic). (3) A3: Higher-grade product, equivalent to API-SL grade (semi-synthetic and full synthetic). (4) A4, A5: Top-tier products, exceeding all current API oil standards. 2. Light-duty diesel engine lubricants are classified into five quality grades: (1) B1: Fuel-efficient, low viscosity, equivalent to API-SJ grade (semi-synthetic and full synthetic). (2) B2: Main product range, equivalent to API-SG and SF grades (mineral oil and semi-synthetic). (3) B3: Higher-grade product, equivalent to API-SL grade (semi-synthetic and full synthetic). (4) B4, B5: Top-tier products, exceeding all current API oil standards.
As an automotive technology enthusiast, I've learned that the A3/B4 marking on engine oil bottles is part of the API standards, specifically designed for high-performance engines. Simply put, A3 indicates suitability for gasoline engines, requiring protection against excessive wear and oxidation at high temperatures; B4 is for certain light-duty diesel engines, commonly found in European models. When combined, this type of oil meets the requirements of both gasoline and diesel vehicles, making it particularly suitable for modern high-performance cars like Mercedes-Benz or Volkswagen. On a related note, if the car's manual specifies A3/B4 oil but the wrong type is used, it could lead to long-term issues such as engine carbon buildup, increased fuel consumption, or reduced power. I always make sure to check this marking during every maintenance session to ensure the engine's longevity—it's a key strategy to save on hefty repair costs.
