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What does 'big oil' and 'small oil' mean?

1 Answers

LaElliott

07/30/25 6:29am

Small oil refers to illegally processed (self-processed and produced) diesel or gasoline, which is cheaper than the fuel from gas stations. CNPC, CNOOC, and Sinopec are collectively referred to as the 'big three oils'. Introduction to gasoline: Gasoline is a volatile and flammable liquid hydrocarbon mixture obtained from the distillation and cracking of petroleum, used as fuel. It appears as a transparent liquid, is flammable, and has a distillation range of 30°C to 220°C. Principle of thermal expansion and contraction: Thermal expansion and contraction refer to the property of objects expanding when heated and contracting when cooled. This occurs because the movement of particles (atoms) within the object changes with temperature. When the temperature rises, the vibration amplitude of the particles increases, causing the object to expand; when the temperature drops, the vibration amplitude decreases, causing the object to contract.

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Where is the car tracker installed in the car?

There are different types of vehicle tracking devices, and their installation locations vary accordingly. They can be divided into the following two types: 1. Hardwired tracking devices: Since they need to be connected to a constant power source, they can be installed near the dashboard, such as the front dome light area or under the front windshield trim panel. 2. Wireless tracking devices: These can be installed in concealed locations like door panels, under the rear windshield trim panel, or inside the front bumper. Below are the functions of a vehicle tracking device: 1. Stolen vehicle alarm: Once enabled, the device will trigger an alarm as soon as the car is started. It provides dynamic positioning, transmitting data every ten seconds to ensure vehicle security. 2. Speed limit setting: Constantly reminds the driver of safe driving. 3. Route playback: Displays the traveled route and the duration of stops.

What to Replace During the Second Car Maintenance?

The second maintenance for a car requires replacing the engine oil, oil filter, gasoline and fuel filter, cleaning or replacing the air filter, cleaning the air conditioning filter, etc. Vehicle maintenance is mainly divided into two aspects: 1. Body cleaning: Interior cleaning every 3-6 months; especially during seasonal changes, attention should be paid to the entire interior, including the air conditioning ducts, under the seats, etc., in addition to the dashboard. For the exterior, wash the car after rain, and promptly clean off bird droppings, insect remains, etc. Wax the car about once a month. 2. Vehicle maintenance: 'Maintenance' is more important than 'repair'; proper maintenance not only ensures safety but also extends the vehicle's service cycle and lifespan, reduces cost expenditures, and achieves twice the result with half the effort.

What is the Principle of Air Suspension?

Here is an introduction to the principle of air suspension: 1. Principle one: The working principle of air suspension is to use an air compressor to form compressed air and adjust the ground clearance of the car through the compressed air. Generally, models equipped with air springs have ground clearance sensors near the front and rear wheels. Based on the output signals from these sensors, the vehicle's computer determines changes in the body height and then controls the air compressor and exhaust valves to automatically compress or extend the springs, thereby achieving a damping effect. 2. Principle two: Air suspension also adds a certain degree of flexibility to the car. When driving at high speeds, the air suspension can automatically stiffen to improve the stability of the body. Conversely, when driving for long periods on uneven low-speed roads, the vehicle's computer will soften the suspension to enhance ride comfort.

What Causes the Belt Noise When the Car Air Conditioner is On?

Car air conditioner belt noise can be caused by the following reasons: 1. Check the belt tension: If the car belt is loose, it will produce a squeaking sound, and the belt tension needs to be adjusted promptly. 2. High pressure in the air conditioning system: When the air conditioner is turned on, the system pressure increases rapidly, requiring professional maintenance to check the pressure. 3. Air conditioner belt slippage: The belt may have quality issues or installation problems. Before installing the belt, the pulley should be cleaned. You can use a cloth or gloves to wipe the entire pulley, but avoid touching the new belt with oily hands, as contact with oil can cause oxidation and slippage. It is recommended to replace the belt at a professional auto repair shop.

Will Car Rust Remover Damage the Paint?

Car rust remover can damage the paint. Here are some car paint maintenance methods: 1. Nano Coating: After applying nano coating, the paint can prevent general scratches, block UV rays, and its good flexibility prevents paint cracking, accelerates water droplet runoff, and avoids water spot lens effect, stains, and oxidation spots. 2. Waxing: Waxing is the most well-known method of paint maintenance. Generally, car wash places offer waxing services. After waxing, it provides a certain level of protection for the paint in the short term. 3. Glazing: Glazing uses high molecular polymers and petroleum-based solvents as main ingredients, pressed into the paint by a polishing machine to form a mesh structure, enhancing the paint's strength and hardness. For a certain period, it protects the paint from minor scratches. Moreover, the 'glaze' is waterproof, feels smooth, and lasts longer than waxing.

What is the Proper Tire Pressure for Cars?

Car tire pressure should be maintained between 2.3-2.5 bar. The hazards of excessive tire pressure are as follows: Impact on braking performance: Excessive pressure reduces tire friction and adhesion, negatively affecting braking effectiveness. Reduced tire lifespan: Accelerates uneven wear on the central tread pattern, decreases tire longevity, increases vehicle vibration, and indirectly shortens the lifespan of other components. Increased load: Causes excessive stretching deformation of tire cords, reduces tire elasticity, and increases the load experienced during driving. Decreased puncture resistance: Makes tires more vulnerable to punctures from sharp objects like nails or glass on the road. Impact forces may cause internal cracks or blowouts, leading to tire bursts.

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