How should trucks be maintained to get through this winter?

Nowadays, major car manufacturers are promoting the concept of maintenance instead of repair. Just like us, if we pay attention to exercise, eat well, drink well, and keep warm, we won't have to worry about getting sick and suffering when the weather changes slightly. Below, let's discuss from four aspects—maintenance, starting, driving, and troubleshooting—how to help your beloved car get through this winter smoothly!

▎Maintenance

Maintenance starts with the choice of oil. Choosing oil is quite simple: in winter, when the weather is cold and the liquid doesn’t flow well, you need to use oil with lower viscosity, what we commonly call slightly thinner oil; in summer, when the weather is hot, naturally choose oil with higher viscosity, meaning thicker oil (we have a detailed explanation about engine oil viscosity at the end of the article).

The two common types of oil for our trucks are 15W40 and 20W50. How should I choose in winter? Generally speaking, 20W50 is suitable for ambient temperatures from -15℃ to 50℃, while 15W40 is suitable for ambient temperatures from -20℃ to 40℃. Knowing this, it becomes clear which type of engine oil we should choose. In practice, in regions north of the Yangtze River, especially Xinjiang or Northeast China, winter oil, that is, 15W40, should be used. For vehicles that operate in the southern regions year-round, such as Guangdong and Hainan, there’s no need to worry, 20W50 is fine all year round.

You might ask, for my Jiefang 460 or 500 horsepower trucks, if only one type of engine oil is used, what type is it? Do I need to take special measures in winter?

Jiefang Super Diesel Engine Oil has a viscosity rating of 10W-40, which means it’s suitable for ambient temperatures between -25℃ and 40℃. The regulation is to change the oil every 100,000 kilometers or once a year, but there are special situations. If the vehicle is used for more than three months in dusty areas, mountainous regions, or cold regions (ambient temperature below -20℃), the oil change interval should be halved. Whichever comes first between mileage and time applies, which means 50,000 kilometers or 6 months, whichever comes first, you should change the oil.

Gear oil. There is no distinction between winter and summer; only the viscosity differs. 

Dongfeng's gear oils generally come in two types, with grades GL-5 85W-90 and GL-5 85W-140. 

The typical operating temperature range is between -15°C and 49°C. The 140 viscosity is higher than the 90, with 90 used for the gearbox and 140 used for the rear axle. 

From GL-1 to GL-6, these numbers represent the quality of the oil—the higher the number, the better the quality. For gears operating under high-speed impact loads, high-speed low torque, or low-speed conditions, GL-5 grade gear oil is specified. Heavy-duty commercial vehicles also use gear oil of this level.

Antifreeze, also known as coolant, is fully called automotive antifreeze coolant. It refers to coolant with antifreeze functions, allowing cars to continue operating in cold winter temperatures. Engine coolant contains certain substances that lower the freezing point of water as antifreeze agents, preventing the cooling system from freezing in low temperatures. When we commonly say -30°C, it means that freezing will occur only when the temperature reaches minus 30 degrees Celsius.
 

▎Starting 

The three major liquids for vehicle maintenance are basically these. Below are some precautions to keep in mind when starting the vehicle: 

The engine electronic control system has a cold start preheating function. When the external temperature is below 0℃, pay attention to whether the preheating indicator on the dashboard lights up. If the preheating light is on, it means the engine is preheating. In this case, do not start the engine until the preheating indicator goes off. 

After starting the engine, let it run at low speed for a few minutes to warm up the engine. Only when the water temperature reaches above 50℃ can you start driving. During the preheating process, observe the operation of all instruments, indicator lights, and warning lights. Be careful not to idle for too long. 

In the early stage of preheating, the oil pressure light, brake system warning light, and parking brake light will be on. However, after the car starts, as oil and air pressure increase, the oil pressure light and brake system warning light will turn off. 

For the Jiefang Linghang version, when the air pressure gauge needle reaches 0.55 MPa, oil pressure reaches 0.1 MPa, and coolant temperature rises above 50℃, the vehicle is ready to start moving. At this time, the parking brake light is still on, reminding you to release the parking brake before starting.

▎Driving

After the vehicle starts normally, diesel needs to be added to it. So how should you choose diesel? The following table can serve as a reference:

After selecting diesel, pay attention to whether there is water in the filter cup below the water separator and drain water frequently.

During normal driving, especially in rainy or snowy weather, don’t drive too fast, keep your visibility clear, maintain enough space from the vehicle in front, and be careful to avoid skidding. These are things experienced drivers already know.

▎Malfunctions

During winter, when temperatures are low, areas with water naturally tend to freeze, especially the components in our brake system, which are crucial for the safety of both people and the vehicle. Therefore, if the dryer hasn’t been replaced for a long time, it needs to be changed now. If there is dirty water in the air storage tank, it should be drained thoroughly.

Besides draining water, there is another issue that is unavoidable in older vehicles: when the weather suddenly turns cold and the temperature drops sharply, some engine oils may contain water.

There are two reasons for this. One is that the rubber sealing rings deteriorate after long-term use and lose their effectiveness. In low temperatures, they lose elasticity, resulting in poor sealing, which allows antifreeze to enter the engine oil.

Another possibility is that the cylinder liner has developed cracks. After the engine starts, uneven heating of the cylinder liner’s interior and exterior creates heat stress, leading to cracks in the liner and water leakage.

Alright, that's all for the precautions to take for vehicles in winter. If anyone has good opinions or suggestions, feel free to leave a comment. By sharing your methods through communication, every truck driver can get through this winter smoothly!

▎ Engine Oil Specifications

Engine oil can be categorized into three types: summer, winter, and all-season oil.

1. Winter oil grades are: 0W, 5W, 10W, 15W, 20W, 25W. The 'W' stands for Winter. The smaller the number before the 'W', the lower the viscosity at low temperatures and the better the flow, making it suitable for lower minimum temperatures;

2. Summer oil grades are: 20, 30, 40, 50. The higher the number, the higher the viscosity, making it suitable for higher maximum temperatures.

3. The all-season oil grades for winter and summer are: 5W/20, 5W/30, paired with 20W/40, 20W/50. The smaller the number for winter use, the better the performance in cold; the larger the number for summer use, the higher the viscosity and the wider the applicable temperature range. 

(1) High-temperature type: the number indicates the viscosity at 100°C; the higher the number, the higher the viscosity.

(2) Low-temperature type: 'W' indicates use only in winter; the smaller the number, the lower the viscosity and the better the low-temperature flow.