What is the Difference Between MIIT Fuel Consumption and Actual Fuel Consumption?

[OAdaline]

Generally speaking, if a car is labeled with 6 liters per 100 km by the MIIT, the actual consumption is at least 7 liters, which is at least 10% higher. The difference between them is related to the following factors: 1. Driving Environment: During the MIIT testing process, the driving environment differs significantly from real-world conditions. The test environment is usually ideal, but in daily life, with increasing traffic and longer congestion times, fuel consumption inevitably rises. 2. Simulated Data: The MIIT uses an indirect measurement method, placing the entire vehicle on a test bench to simulate actual road speeds under specific conditions (idling, acceleration, constant speed, deceleration, etc.). The vehicle's emissions of carbon dioxide, carbon monoxide, and hydrocarbons are measured, and fuel consumption is calculated using the carbon balance method. In practice, this involves measuring exhaust flow rates and the concentration of carbon-containing gases to estimate fuel consumption. However, the entire test is conducted under controlled conditions, which, while relatively fair, often yields data representing the vehicle's fuel consumption in an ideal state. 3. Driving Habits: Everyone's driving habits vary. Experienced drivers who pay attention to fuel consumption know how to shift gears or adjust speed to reduce consumption. However, many beginners may have habits like pressing the accelerator hard or frequently revving in low gear, and some drivers prefer aggressive driving, leading to significantly higher actual fuel consumption than the MIIT figures. Additionally, using the air conditioning in hot weather naturally increases fuel consumption. 4. Wind Resistance: Some drivers habitually open windows while driving, which increases wind resistance. This not only fails to save fuel but actually increases consumption. 5. Increased Load: During fuel consumption tests, the vehicle is often empty. In daily use, however, cars are frequently fully loaded or carry three to four passengers, and the trunk is rarely empty. Increased vehicle weight inevitably leads to higher fuel consumption.