The numbers on the rear of cars of different brands have different meanings.

1. Represents the car model: such as CA6173, TJ7130U, Santana2000, Santana3000, A6, A8, X5, X3, XC90, S80, S40, etc. The numbers here only represent the model, which has its own special features Numbering rules;

2. Represent the displacement of the car: Some use numbers with decimal points such as 1.6, 1.8, 2.0, 3.0 to represent the displacement of the car: 1.6 liters, 1.8 liters, 2.0 liters, 3.0 Literations, some use 350, 430, 500, etc. to represent the car's displacement of 3.5 liters, 4.3 liters, 5.0 liters, etc.

3. Represents the model reflecting the displacement size: typically a BMW, 525 represents a 5 Series car with a 2.5-liter displacement, and 740 represents a 7 Series car with a 4.0-liter displacement.

Extended information:

The pinyin letters are usually followed by 4 Arabic numerals. The first digit from the left of a car is "7", and the middle two digits are the engine number of that model of car. For example, "08" means the engine displacement is 0.8 liters, "20" means 2.0 liters, and "16" means 1.6 liters; after the number indicating the displacement, there is a digit indicating the company's customized product serial number.

For example, Changan Suzuki's "Antelope 1300" sedan has a displacement of 1300CC, which is 1.3 liters. Another example is the Palio sedan produced by Nanjing Fiat. You can see the words "1.3" and "1.6" on the side of the car body. This is their engine displacement, in liters.

As for FAW-Volkswagen's Audi series sedans, their displacement is written on the rear of the car. For example, "1.8T" means that the displacement is 1.8 liters with turbocharging, and "2.4" means that the displacement is 2.4 liters.