At how many kilometers should a major car maintenance be performed?

[DiAaliyah]

Major maintenance refers to maintenance that includes engine care and is typically performed every 60,000 kilometers. Major maintenance is based on minor maintenance, with the two types of maintenance alternating. Minor maintenance includes oil changes, and generally, there are three types of engine oil: 1. Full synthetic: Full synthetic oil should be changed every 10,000 kilometers or once a year. 2. Semi-synthetic: Semi-synthetic oil should be changed every 7,500 kilometers or every 7-8 months. 3. Mineral oil: Mineral oil should be changed every 5,000 kilometers or every six months. Below is an introduction to the three types of engine oil: (1) Full synthetic oil: Synthetic oil is a man-made oil. During its production, various natural substances are chemically decomposed and then synthesized with other substances to finally produce synthetic oil. (2) Semi-synthetic oil: Semi-synthetic oil is a lubricant made using semi-synthetic base oil, which is refined from international Group III base oil through hydrocracking technology. It is a mixture of mineral oil and full synthetic oil in a 4:6 ratio. The purity of semi-synthetic oil is very close to that of full synthetic oil, but its cost is slightly higher than that of mineral oil. It is an ideal transitional product from mineral oil to synthetic oil. (3) Mineral oil: As the name suggests, mineral oil is extracted from minerals and is relatively viscous. Mineral oil is refined from petroleum base oil and then mixed with additives.

[StAdrian]

To be honest, major maintenance isn't strictly about mileage. From discussions in car owner groups, I've noticed people often overlook how vehicle age affects part deterioration. Fluids like brake fluid and transmission fluid should be changed after 3 years even if the mileage hasn't reached 50,000 km. I've seen too many cases where people only checked mileage, leading to deteriorated fluids damaging components. Especially when switching to winter tires in northern regions, having mechanics check the chassis rubber bushings' aging condition for just five minutes might save thousands in repair costs.

[DiEverett]

The most common issue I encounter during car repairs is that owners rely too much on the recommended mileage in the manual. In fact, the core of major maintenance is conducting a comprehensive inspection. When your car reaches around 60,000 kilometers, besides the routine oil and three-filter changes, you must check the spark plug gap (factory platinum spark plugs can last up to 80,000 kilometers at most). At the very least, open the transmission oil cap to check its color—replace it immediately if it's black or smells bad. For power steering fluid and brake fluid, it's recommended to use test strips to check the water content. The most easily overlooked tasks are cleaning the throttle body and intake manifold carbon deposits, which have a significant impact on fuel consumption.

[SaraMarie]

A veteran taxi driver with 20 years of experience tells you that major maintenance depends on the actual condition of the car. For city commuter cars, doing it at 60,000 km is perfectly fine, but for those like me who drive on highways every day, it's necessary to check the chassis bushings and ball joints at 40,000 km. Besides the usual fluids, key inspection items should include: 1. Whether the water pump bearing has abnormal noise, 2. The wear level of the generator carbon brushes, 3. Cracks in all chassis rubber components. If any of these three fail on the highway, the repair cost could equal five major maintenance services.

[Dorothy]

During used car evaluations, I've noticed many misconceptions about major maintenance. In reality, the condition of the three major components is far more important than the odometer reading. For example, it's common to replace the clutch three-piece set in manual transmission vehicles at 100,000 km, while automatic transmissions require checking the transmission fluid condition at 70,000 km. Key inspection items include: timing belt (dangerous if over 60,000 km), cracks in the alternator belt, clogged radiator condenser layers from insects, and brake disc thickness (must replace if below 3mm). Remember: engine oil can be changed yourself, but transmission fluid must be completely replaced using a machine circulation method.

[Renee]

My experience with car modifications has taught me that the most crucial upgrade during major maintenance is the inspection items. It is recommended that owners request a thorough inspection every 50,000 kilometers: 1. Endoscopic inspection of carbon deposits in the cylinders (mandatory for direct-injection vehicles). 2. Four-wheel alignment to adjust the camber angle (prevents uneven tire wear). 3. Visual cleaning of the air conditioning evaporator (prevents odors). 4. Use an OBD scanner to check fuel trim values (assesses carbon deposit levels). Special reminder for owners who have modified their engines: turbocharged vehicles should have their oil changed 2,000 kilometers earlier, and those with ECU tuning should check cylinder pressure and ignition coil conditions.