Failure to change the engine oil for an extended period will cause multi-faceted damage to the engine, primarily manifested as comprehensive deterioration in lubrication efficacy, sealing performance, and cooling capacity. Severe cases may result in cylinder scoring or crankshaft seizure, with repair costs potentially reaching tens of thousands of ringgit. Concurrently, compromised sealing performance in degraded oil leads to combustion chamber blow-by, reducing power output by 15%-20%, while diminished cooling efficiency increases overheating risks that may cascade to electronic system damage. Economically, heightened frictional resistance increases fuel consumption by 10%-15%, while long-neglected vehicles may incur maintenance costs 50-fold higher than regularly serviced counterparts, with significantly depreciated resale value. Adherence to oil-specific replacement intervals is imperative: mineral oil every 5,000 km or 6 months; semi-synthetic every 7,500 km or 9 months; full-synthetic every 10,000 km or 12 months-with reduced intervals for frequent stop-and-go driving. Periodic oil condition inspections coupled with genuine filter replacements constitute essential practices for sustained engine performance.
