What should be paid attention to when driving on mountain roads?

How to Identify Engine Oil Grades?

Methods to identify engine oil grades: The 'S' series represents oil for gasoline engines, while 'C' denotes oil for diesel engines. When both 'S' and 'C' appear simultaneously, it indicates a universal oil suitable for both gasoline and diesel engines. The oil quality ranges from SA up to SL, with later letters in the alphabet indicating higher quality grades. Each subsequent letter signifies improved performance over the previous one, as the oil contains more additives to protect the engine. The oil grades for winter and summer also differ. Winter oil grades are: 0W, 5W, 10W, 15W, 20W, and 25W. The symbol 'W' stands for 'Winter,' and a smaller number before 'W' indicates lower low-temperature viscosity, better low-temperature fluidity, and suitability for lower minimum temperatures. Summer oil grades are: 20, 30, 40, and 50, where a larger number indicates higher viscosity and suitability for higher maximum temperatures.

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How to Clean the Outside of a Car Radiator?

Methods for cleaning the outside of a car radiator: 1. Before cleaning, remove the bumper. Ensure all fixing screws are unscrewed during removal, and slowly detach it from both ends towards the middle to avoid breaking the fixing clips; 2. After removing the bumper, the radiator's position can be seen. Adjust the water gun nozzle to a spray pattern and set the pressure to an appropriate level, then rinse the dirty surface of the radiator; 3. After rinsing, check if any cooling fins are damaged. If so, use tweezers or a bamboo skewer to straighten them. Once all checks are complete, reinstall the bumper in the reverse order of removal to finish cleaning the radiator.

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What letter represents fully synthetic engine oil?

Fully synthetic engine oil does not have a letter designation. The API of engine oil only represents the oil grade, and there is no necessary connection between the oil grade and whether it is fully synthetic. For example: SN grade is currently a higher grade, but SN grade does not necessarily mean it is all fully synthetic engine oil; there are also semi-synthetic oils. There are two designations for engine oil: one is SAE, and the other is API. SAE is used to indicate the viscosity of the oil, while API is used to indicate the grade of the oil. API is the abbreviation for the American Petroleum Institute, indicating the quality level of the oil. The API designation consists of two letters: the first letter, if it is S, indicates gasoline engines, and if it is C, it indicates diesel engines.

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What does the R gear mean in a car?

In a car, the R gear stands for the reverse gear, which is one of the three standard gears in a vehicle. Its function is to enable the car to move in the opposite direction, allowing it to reverse, a feature essential for any automobile. In manual transmission models, the reverse gear also serves as a hill-hold function, where parking on a downhill slope can be secured by engaging the reverse gear to mechanically lock the drive shaft. The method of using the reverse gear is as follows: 1. For manual transmission models: After bringing the vehicle to a complete stop, depress the clutch and brake pedals, then shift into reverse gear, followed by a slight throttle application while partially engaging the clutch. 2. For automatic transmission models: To engage or disengage the R gear, the driver must press the brake pedal and simultaneously press the safety button on the gear lever or push down the gear selector.

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Will a misfiring cylinder trigger the check engine light?

Misfiring cylinders will trigger the check engine light, usually a yellow warning light. Engine misfire primarily refers to one or more cylinders not functioning properly. After an engine misfire occurs, it can lead to increased fuel consumption, black smoke emissions, weak acceleration, severe shaking, and louder engine noise. It also makes the vehicle prone to stalling. To diagnose a misfiring cylinder, observe noticeable body shaking at idle. Check the exhaust pipe outlet—the exhaust flow will show obvious intermittency, accompanied by significant pipe vibration and a distinct "popping" sound. Additionally, at low RPMs around 2000, the vehicle body shakes noticeably with weak acceleration, while the shaking sensation reduces at higher RPMs. This phenomenon is often related to ignition coil issues.

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How to Determine When to Replace Tires?

Methods to determine when to replace tires are: 1. Check the wear indicators. Tires have small raised platforms in the tread grooves or triangular symbols marked on both sides of the tire. Once the tread wears down to these indicators, the tire should be replaced or retreaded. 2. Examine tire uneven wear. If the center of the tire is severely worn while the sides are not, or if one side is significantly more worn than the other, the tire needs to be replaced as soon as any side reaches the wear indicator. 3. Inspect the tire sidewalls. If there are bulges or cracks on the sidewalls, it indicates that the tire cords may be broken or severely aged. To prevent blowouts while driving, it is recommended to replace the tire immediately. 4. Assess the degree of tire aging. If the tire shows signs of aging, such as numerous small cracks in the tread grooves or sidewalls that are close to damaging the tire body, replacement is necessary. Severely aged tires are prone to blowouts under high temperatures.

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What should be paid attention to when driving on mountain roads?

How to Identify Engine Oil Grades?

How to Clean the Outside of a Car Radiator?

What letter represents fully synthetic engine oil?

What does the R gear mean in a car?

Will a misfiring cylinder trigger the check engine light?

How to Determine When to Replace Tires?

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How many times can I retake the Subject 1 exam if I fail?

Why does the car shake violently when it is just started?

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