Long-term failure to change engine oil can indeed cause severe damage to the engine, primarily manifested as diminished lubrication efficacy, impaired heat dissipation capacity, and loss of cleaning function. Engine oil serves critical roles in lubricating metal components, dissipating heat, and suspending contaminants within the engine. Documented cases demonstrate that neglected engines may develop cylinder scoring or crankshaft seizure, with repair costs potentially exceeding tens of thousands of ringgit. Moreover, degraded oil exhibits 30%-50% reduction in thermal conductivity, increasing risks of engine overheating that may trigger electronic system malfunctions or seal degradation. Approximately 5 grams of metallic particulates generated per 1,000 kilometres accumulate as sludge, obstructing oil galleries and contaminating precision assemblies including turbochargers. Manufacturers recommend adherence to specified maintenance intervals (mineral oil: 5,000 km/6 months; full synthetic: 10,000 km/12 months), with reduced replacement cycles advised for frequent short trips or stop-and-go traffic conditions. Regular oil changes preserve engine performance while preventing ancillary costs including 10%-15% elevated fuel consumption and 30%-40% depreciation in used vehicle resale value.
