What are the question types for Subject 4 exam?

Is it okay if the car didn't stall when driving through a puddle?

If the car didn't stall when driving through a puddle, a comprehensive inspection should be conducted. Here are some precautions for driving through deep water: Avoid excessive speed: First, do not drive too fast. Use a low gear to enter the water smoothly and proceed slowly to prevent water splashes from wetting the engine's electrical components, which could cause the engine to stall. Maintain steady acceleration: Keep the accelerator pedal steady to ensure smooth and sufficient power for the car. Try to avoid shifting gears, stopping, or making sharp turns midway. While driving, look ahead and focus on distant fixed objects rather than the water surface to prevent visual disorientation and deviation from the intended water-crossing route.

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What is the diameter of a 21-inch wheel hub in centimeters?

The diameter is 53.34 centimeters. 21 inches refers to the diameter of the wheel hub, where 1 inch equals 2.54 centimeters. 21 * 2.54 = 53.34 centimeters. This is not an exact value but rather an approximate figure. Wheel diameter: The wheel diameter affects the driving force of the engine. The larger the diameter, the greater the driving force required by the engine. In stop-and-go city driving conditions, larger tire diameters result in higher fuel consumption, while smaller tire diameters offer better fuel efficiency. Aspect ratio: Generally, the larger the aspect ratio, the thicker the tire sidewall and the greater the rolling resistance. Tires with smaller aspect ratios have thinner sidewalls, resulting in less deformation at the contact patch with the ground, lower dynamic resistance, and better fuel efficiency. In addition to the model, tires also display the following common data: Tire cord material: Indicated by Chinese pinyin, such as M for cotton cord, R for rayon cord, N for nylon cord, G for steel cord, and ZG for steel radial cord tires. Speed rating: Indicates the maximum speed at which the tire can carry a specified load under defined conditions. Letters A to Z represent certified speed ratings ranging from 4.8 km/h to 300 km/h. Common speed ratings include: Q: 160 km/h; H: 210 km/h; V: 240 km/h; W: 270 km/h; Y: 300 km/h. Rim specification: Indicates the rim size compatible with the tire for practical use, e.g., standard rim 5.00F.

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Can two vehicles under the same owner swap license plates?

Two vehicles under the same owner can swap license plates, but certain conditions must be met. The specific conditions are as follows: Owner and vehicle classification: To swap license plates between different vehicles under the same owner, the owner must be the same person, including matching name and ID card. Starting from June 1, 2019, such swaps are permitted. License plate swaps between different vehicles under the same owner do not apply to commercial vehicles; only non-commercial vehicles are eligible for swaps. Additionally, both vehicles must be of the same classification and must have the same type of license plate. Timeframe: If a license plate swap between different vehicles has already been applied for within one year, another swap can only be applied for after a full year has passed, with no changes permitted in between.

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What are the symptoms of a slight malfunction in the idle motor?

Idle motor slight malfunction symptoms include unstable idle speed, engine stalling at too low idle speed, and slow acceleration with poor performance. Relevant information about the idle motor is as follows: Introduction: The idle motor is a component that controls the idle speed of motor vehicles. When the engine is running without load, it is referred to as idling. During idling, the cross-sectional area of the idle air passage is adjusted based on the engine temperature and load to ensure optimal idle speed under various conditions. Function: The idle motor is primarily responsible for maintaining the car's idle speed, aiming to adjust the idle according to the engine load during idling. The idle stepper motor is mounted on the throttle body and controlled by the engine control unit to manage the engine idle speed. When the engine speed deviates from the idle speed, the throttle valve regulates the amount of air entering the intake manifold, which is mechanically operated by the accelerator pedal cable.

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What Causes Noise After Installing New Tires?

After replacing new tires, abnormal noise may occur due to potential bearing issues caused during the tire replacement process. Other reasons: If the tires were replaced by the owner or the mechanic failed to perform proper wheel alignment after replacement, it may result in uneven tire load distribution and "tire scrubbing" phenomenon. New tires with lower aspect ratios or increased width will generate more noise, depending on the owner's preference. Reasons for loud tire noise: Foreign objects may be stuck in the tire tread gaps, which can be checked and removed. It could also be due to excessive tire pressure or uneven pressure among tires, requiring verification at a repair shop.

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What does it mean when the engine boost shows 0?

This is a normal phenomenon. At idle speed, the turbocharger is not working and has no effect, so it shows 0. The engine boost system compresses air in advance and supplies it to the cylinders to increase air density and intake volume. Increasing the engine's air intake allows for more fuel to be supplied in the cycle, thereby increasing engine power. This results in good acceleration performance and improved fuel economy. Engine Introduction: An engine is a machine that can convert other forms of energy into mechanical energy, including internal combustion engines, external combustion engines, jet engines, electric motors, etc. For example, an internal combustion engine usually converts chemical energy into mechanical energy. The term engine can refer to the power generation device or the entire machine including the power device. The earliest engines were born in the UK. Engine Classification: Engines are divided into external combustion engines and internal combustion engines.

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What are the question types for Subject 4 exam?

Is it okay if the car didn't stall when driving through a puddle?

What is the diameter of a 21-inch wheel hub in centimeters?

Can two vehicles under the same owner swap license plates?

What are the symptoms of a slight malfunction in the idle motor?

What Causes Noise After Installing New Tires?

What does it mean when the engine boost shows 0?

What are the causes of abnormal noise from the clutch pedal?

How Long After Registration Can You Take the Subject 1 Test?

What to Do When the Windshield Washer Fluid Freezes and Causes the Motor to Stop Responding?

Can You Lock the Car with Windows Open?