What details should be paid attention to when buying a used car?

What are the hazards of engine knocking?

When knocking occurs, it is accompanied by shock waves, causing vibrations and producing a metallic knocking sound. In mild cases, it affects normal comfort, while in severe cases, it can have adverse effects on the engine. The hazards are as follows in three aspects: 1. Decline in engine economy and power performance: When slight knocking occurs in a gasoline engine, it approaches constant-volume combustion, slightly improving power and thermal efficiency. However, during moderate or severe knocking, the sudden increase in pressure and temperature at the knocking site generates multiple pressure shock waves. These shock waves reflect multiple times between the cylinder walls, piston top, and combustion chamber ceiling, creating high-frequency oscillations. The shock waves disrupt the laminar boundary layer on the cylinder walls, significantly increasing heat transfer to the outside, raising heat loss, and reducing output power, thereby decreasing the engine's economy and power performance. 2. Reduced reliability of engine components: During knocking in a gasoline engine, the rate of pressure rise and maximum explosive force increase, with the rate of pressure rise being 4 to 8 times that of normal combustion. This imposes tremendous stress on engine components, accelerating wear on piston connecting rod bearings and main bearings. 3. Worsened engine emissions: During knocking combustion, the increased temperature in the combustion chamber accelerates the decomposition of combustion products into CO, HC, and NOx. In severe cases, the liberated free carbon does not have enough time to form CO2 and is expelled with the exhaust, increasing the PM content in the exhaust and aggravating air pollution.

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What Are the Autonomous Driving Products?

Tesla Autopilot 2.0 autonomous vehicles, Apollo 2.5 autonomous vehicles, Dongfeng unmanned L4 intelligent trucks, and Shenzhen autonomous buses. The following is an expansion on autonomous vehicles: Definition of autonomous vehicles: Autonomous vehicles, also known as driverless cars or computer-driven cars, are unmanned ground vehicles with transport power. As automated vehicles, autonomous cars can sense their environment and navigate without human operation. Fully autonomous vehicles are not yet fully commercialized; most are prototypes and demonstration systems, with some reliable technologies gradually being incorporated into mass-produced models, making them a reality. There are six levels of autonomous driving: Level 0 (LO) is completely driver-operated; Level 1 (L1) means the car can assist the driver in certain driving tasks under specific conditions; Level 2 (L2) allows the autonomous system to complete certain driving tasks, but the driver must constantly monitor the environment and be ready to take over in dangerous situations—this is the current level of autonomous technology achieved by many autonomous vehicles; Level 3 (L3) means the driver rarely needs to be ready to take over, as the car can perform all actions independently; Levels 4 (L4) and 5 (L5) represent full autonomous driving technology, where the car no longer requires driver intervention—the difference being that L4 is fully independent only under specific conditions like highways, while L5 operates under any conditions.

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Can I retake the motorcycle test without waiting for 10 days?

You cannot retake the motorcycle test without waiting for 10 days. Here is the relevant introduction to the motorcycle test: Test items: There are three subjects in the test. For the first subject of the motorcycle test, you are generally required to answer 50 questions, with each question worth 2 points, and the test duration is 45 minutes. The second subject is the motorcycle slalom test. The fourth subject mainly includes the identification of various road signs, traffic police hand signals, and the handling methods for various situations encountered while riding a motorcycle. The results are given on the spot, the same as the first subject. After passing, you sign and wait for the oath-taking ceremony later. Annual inspection: Motorcycle driving licenses do not require annual review. After the implementation of the "Regulations on the Application and Use of Motor Vehicle Driving Licenses," the annual review of driving licenses has been canceled, and they are replaced every 6 years (the replacement time can be known by checking the validity period on the driving license). However, B1, B2, A1, A2, and A3 licenses (formerly A and B licenses) must submit a medical examination form to the vehicle management office in the issuance month of the driving license every year. Other licenses do not require annual medical examinations. Motorcycle driving licenses do not require annual medical examinations.

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What does SD at the beginning of a license plate mean?

SD at the beginning of a red license plate refers to the license plate of the former Shenyang Military Region Equipment Department. Red license plates are used for military vehicles, while black plates with white characters are for foreign-related vehicles. License plates for legal and political departments such as public security, courts, procuratorates, state security, and judicial authorities, as well as police cars, armed police vehicles, and military vehicles of the People's Liberation Army, are all white plates. Here are the relevant details: 1. The first uppercase letter in the license plate represents the initial letter of the local military region's pinyin. 'Shenyang' is the pinyin for Shenyang, with 'S' representing the Shenyang Military Region. 2. The second letter is the prefix, using uppercase English letters, which are common across major military regions. For example: 'A' represents the headquarters, 'B' represents the political department, 'C' represents the logistics department, 'D' represents the equipment department, 'H' represents warehouses and retirement homes, and 'S' represents logistics factories. This type of license plate belongs to the '2012-style' military vehicle license plate, which is the seventh generation of military vehicle license plates, officially put into use from May 1, 2013. The new-style military vehicle license plates issued this time are the seventh generation of military vehicle license plates in our army.

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What is the fuel consumption of the Auman GTL460 automatic transmission?

The Auman GTL460 automatic transmission consumes approximately 32 liters per 100 kilometers. Reasons for increased fuel consumption: 1. Poor driving habits: A vehicle's fuel consumption is not only related to the car itself but also to the driving conditions and the driver's habits. If you often drive on roads with severe traffic congestion, the fuel consumption will be relatively high. If driving habits are poor, fuel consumption may also increase. 2. Frequent stop-and-go driving: When driving on congested roads, the car often needs to stop and start. Starting from a standstill requires significant kinetic energy, and the engine needs to output substantial power. If frequent stop-and-go driving is necessary, the car's fuel consumption will inevitably rise. 3. Idle conditions: When driving on congested roads, the engine spends some time in idle mode. During idle conditions, the car's driving distance does not increase, but the engine continues to consume fuel, which can also affect the vehicle's fuel consumption per 100 kilometers. If you want to save fuel, the primary task is to change your driving habits: 1. When driving, try to avoid sudden acceleration and deceleration as much as possible, and maintain a steady speed. Only in this way can the car achieve optimal fuel efficiency. 2. In daily use, it is essential to maintain your car regularly to keep it in good condition, which can improve fuel efficiency. During maintenance, always use genuine fluids and parts.

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Where to Get a Physical Examination for Driving School?

Generally, hospitals at or above the second-class A level can conduct physical examinations for driving school. These hospitals have specialized departments for driving school physical examinations. When getting the examination, there is no need to register; simply bring the specialized physical examination form provided by the driving school to a second-class A level or above hospital. The cost of the examination varies depending on the hospital and the specific items included. The examination items are as follows: 1. Height: Applicants for large buses, tractors, city buses, large trucks, or trolleybuses must be at least 155 cm tall. Applicants for medium-sized buses must be at least 150 cm tall. This is the first step in the driving school physical examination. 2. Vision: Applicants for large buses, tractors, city buses, medium-sized buses, large trucks, trolleybuses, or trams must have naked or corrected visual acuity of at least 5.0 on the logarithmic visual acuity chart. For other vehicle types, the requirement is at least 4.9. 3. Color Vision: No red-green color blindness. This is consistent with the vision requirements in the driving school physical examination. 4. Hearing: Able to distinguish the direction of sound sources with each ear at a distance of 50 cm from a tuning fork. 5. Upper Limbs: Both thumbs must be intact, and each hand must have at least three other fingers intact, with normal limb and finger movement. 6. Lower Limbs: Normal movement function. For manual transmission vehicles, the length difference between the lower limbs should not exceed 5 cm. For automatic transmission vehicles, the right lower limb must be intact. 7. Trunk and Neck: No movement dysfunction.

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What details should be paid attention to when buying a used car?

What are the hazards of engine knocking?

What Are the Autonomous Driving Products?

Can I retake the motorcycle test without waiting for 10 days?

What does SD at the beginning of a license plate mean?

What is the fuel consumption of the Auman GTL460 automatic transmission?

Where to Get a Physical Examination for Driving School?

Can motorcycles go on highways in Xi'an?

What Causes Difficult Gear Shifting in Manual Transmission Cars?

Can Different Antifreeze Be Mixed?

Should a Newly Purchased Car Be Fully Wrapped with Film?