How should trucks be maintained to get through this winter?

Winter has arrived, and we add clothes to keep warm, but what should we do about our vehicles? 

Nowadays, major manufacturers are promoting the concept of maintenance instead of repair, just like with ourselves: if we exercise regularly, eat well, and keep warm, we won't worry about getting sick and suffering when the weather changes slightly. Next, let's look at how to help our beloved cars get through this winter from four aspects: maintenance, starting, driving, and handling breakdowns!

▎Maintenance

Maintenance starts with the choice of oil. The principle of choosing oil is simple: in winter, when the weather is cold and liquids don’t flow well, you should use oil with lower viscosity, what we commonly call slightly thinner oil; in summer, when the weather is hot, naturally, you should use oil with higher viscosity, thicker oil (at the end of the article, we have a detailed explanation of engine oil viscosity).

For our trucks, we commonly use two types: 15W40 and 20W50. So how should I choose in winter? Generally speaking, 20W50 is suitable for ambient temperatures from -15℃ to 50℃, while 15W40 is suitable for -20℃ to 40℃. Knowing this makes it clear which type of engine oil we should choose. In practice, in areas north of the Yangtze River, especially Xinjiang or the northeast regions, winter engine oil, namely 15W40, should be used. For vehicles that operate year-round in the south, such as in Guangdong or Hainan, there’s no need to worry; just consistently use 20W50.

Some truck enthusiasts might ask, so for my FAW Jiefang 460 and 500 horsepower engines, there's only one type of engine oil used. What exactly is this oil? Do I need to take any special measures in winter?

The FAW Jiefang super diesel engine oil has a viscosity grade of 10W-40, which means it’s suitable for ambient temperatures between -25°C and 40°C. It is recommended to change the oil every 100,000 kilometers or once a year. However, there are special circumstances: if the engine is used for more than three months a year in dusty areas, mountainous regions, or cold areas (ambient temperature below -20°C), the oil change interval should be halved. Whichever comes first between mileage and time should be the standard, which means changing the oil every 50,000 kilometers or every 6 months, whichever comes first.

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

Dongfeng gear oil generally comes in two types, rated 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 the 90 used in the gearbox and the 140 used in the rear axle. 

From GL-1 to GL-6, the 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, and low-speed conditions, GL-5 gear oil is specified. Heavy-duty commercial vehicles also use this grade of gear oil.

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°C.
 

▎Starting 

The three major fluids 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 light on the dashboard is on. If the preheating light is on, it indicates that the engine is preheating. Do not start the engine until the preheating indicator light goes off. 

After starting the engine, run it at low speed for a few minutes to preheat the engine. Only start driving once the water temperature reaches above 50℃. During the preheating process, observe the operation of all gauges, indicator lights, and warning lights. Avoid running the engine at idle for a long time. 

In the early stages of preheating, the oil pressure light, brake system warning light, and parking brake light are on. However, after the vehicle starts, as oil and air pressure increase, the oil pressure light and brake system warning light will go off. 

For the Jiefang Navigation Edition, when the air pressure gauge reaches 0.55MPa, the oil pressure reaches 0.1MPa, and the coolant temperature is above 50℃, the vehicle is ready to move. 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? You can refer to the table below:

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 know.

▎Malfunction

During winter, when the temperature is low, areas with water naturally tend to freeze, especially parts of our braking system, which are crucial for the safety of both the driver and passengers. Therefore, if the dry bucket hasn’t been replaced for a long time, it needs to be changed, and any dirty water in the air storage tank should be completely drained.

Apart from draining water, there is another phenomenon that cannot be avoided in older vehicles: when the weather suddenly becomes cold and the temperature drops sharply, there may be water in some engine oils.

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 thermal 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 any good advice or suggestions, feel free to leave a comment. Through sharing and communication, everyone can exchange their useful tips to help every truck driver get through the winter smoothly!

▎ Engine Oil Specifications

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

1. Winter oil grades are 0W, 5W, 10W, 15W, 20W, and 25W. The 'W' stands for Winter. The smaller the number before 'W', the lower the oil's low-temperature viscosity, meaning it flows better in cold conditions and is suitable for lower minimum temperatures;

2. Summer oil grades are 20, 30, 40, and 50. The larger 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 cold-weather performance; the larger the number for summer use, the higher the viscosity, suitable for a wider 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 fluidity.