Is it okay if I forgot to change the engine oil after exceeding 5,000 kilometers?

[AliyahMarie]

There's no major issue. Generally, semi-synthetic engine oil performs best within a mileage range of 3,500-5,000 kilometers. Therefore, changing the oil at 4,000-5,000 kilometers is somewhat wasteful and regrettable. You can extend it to 5,500-6,500 kilometers before changing. Additionally, while fully synthetic oil is recommended for replacement at 10,000 kilometers, in practice, it can be changed between 11,000-12,000 kilometers. Below is an introduction to engine oil functions: 1. Lubrication and friction reduction: Forms an oil film between two sliding surfaces to prevent direct metal-to-metal contact, ensuring smooth operation. 2. Cleaning and dispersion: High-quality oil can flush away surface contaminants and adsorb tiny metal particles in the engine, which are then scraped into the oil pan by piston rings. 3. Cooling: When oil reaches operating components, it absorbs and carries away heat, assisting in component cooling. 4. Sealing: Creates an oil film seal between piston rings and cylinder walls to prevent combustion gases from leaking into the crankcase.