What type of engine oil does the BJ40 use?
4 Answers
BJ40 uses 5W-40 engine oil as specified by the manufacturer. The entire BJ40 series is equipped with turbocharged engines, so it is recommended to use full synthetic oil with a viscosity of 40. Turbocharged engines have higher requirements for engine oil. The BJ40 uses factory-recommended oil, but if you wish to change the oil during later maintenance, you can choose from brands such as Shell, Mobil, Castrol, or Total. The viscosity of engine oil changes with temperature, so it is important to pay attention to its performance under both low and high temperatures. For example, in 5W-30, the first number indicates low-temperature fluidity, where 5W means it can withstand temperatures as low as -30°C. The smaller this number, the better the low-temperature fluidity, ensuring smoother cold starts for the car. The second number represents the kinematic viscosity of the oil at 100°C. A higher number means the oil can maintain its viscosity better at high temperatures, which can also be understood as better lubrication performance under high-temperature conditions. The method for changing the oil in the BJ40 is as follows: Wait for the engine temperature to cool down, allowing the oil to flow back into the oil pan. Use a wrench to loosen the oil drain plug and place an oil pan underneath to catch the old oil until it stops flowing. Start the engine for about 30 seconds to allow the oil in the main oil passages to drain out. Use a specialized wrench to remove the oil filter. Apply oil to the gasket of the new oil filter and tighten it clockwise by hand. Add the new engine oil through the oil filler cap on the engine valve cover. Typically, fill about three-quarters of the oil container. Start the engine and let it run for 5 minutes, checking for any leaks around the oil drain plug and oil filter. If leaks are found, perform necessary repairs. After stopping the engine, pull out the dipstick to check that the oil level is within the standard range.
I previously did specialized research on the BJ40's engine oil issue. The manual clearly states the recommendation for 5W-30 or 5W-40. My own car currently uses Shell 5W-40 fully synthetic oil, which gives me extra peace of mind especially during long summer trips. For friends in northern regions, 5W-30 would be more suitable due to its better low-temperature fluidity, making morning starts particularly smooth. The oil capacity is approximately 3.8 liters—keep an eye on the dipstick markings when filling. Oh, and never opt for cheap counterfeit oil; it's best to go to authorized dealers. I once tried a Taobao seller claiming it was genuine, but after 2,000 km the engine noise noticeably increased. I recommend changing every 8,000 km, or earlier at 7,000 km if you frequently go off-roading.
I've been driving the BJ40 for three years and have quite some experience with engine oil. The manual suggests both 5W-30 and 5W-40 are acceptable. I've been using Castrol 5W-30 full synthetic long-term, which is particularly fuel-efficient for city driving. Last week, while helping a fellow car owner with a check-up, I noticed they were using 10W-40, which isn't quite suitable as it makes cold starts difficult in winter. Friends in the south can opt for 5W-40 in summer for better high-temperature resistance. Remember to change the oil filter when changing the oil—last time I forgot, and mixing new oil with old residue was a real waste. For diesel versions, make sure to choose specialized oil with C3 certification. A quantity of 3.5 to 4 liters is sufficient; adding too much increases crankshaft resistance, directly raising fuel consumption.
According to the BJ40 maintenance manual, the safest choices for oil grades are 5W-30 or 5W-40. I highly recommend full synthetic oil, and brands like Mobil or Total are excellent options. Last winter when temperatures dropped to -15°C, my car with 5W-30 oil started right up with a single ignition. Off-road enthusiasts are advised to use 5W-40, as it prevents the oil temperature from getting too high during continuous uphill climbs. Just fill the oil to the middle mark on the dipstick, and make sure not to exceed the upper limit. Regularly check the oil color; if it turns black and thick, it's time for a change. Full synthetic oil can easily last for 8,000 kilometers before needing a replacement—don't fall for the dealership's suggestion to change it at 5,000 kilometers.
