What happens when you don't change your oil filter?

Failing to replace the oil filter for a long time will seriously affect the engine's performance and service life. As a key component for filtering oil impurities, once the oil filter fails, it will cause blockage by pollutants such as metal debris and sludge adsorbed on the filter paper, triggering the bypass valve to allow unfiltered oil to directly enter the engine circulation. This will accelerate the wear of precision components like pistons and cylinder liners. Meanwhile, the accumulation of impurities will reduce the lubrication efficiency of the oil, leading to problems such as weakened power, increased fuel consumption (possibly by 15%-20%), and abnormal black smoke. In severe cases, it may even cost thousands to tens of thousands of ringgit for engine overhaul. It is worth noting that inferior filters will fail prematurely. It is recommended to choose original equipment manufacturer (OEM) or certified brand parts and replace them synchronously with the oil (every 5,000 kilometers for conventional mineral oil and every 10,000 kilometers for fully synthetic oil). If extended-life oil is used, a matching extended-life oil filter is required. Additionally, in dusty environments or with frequent short-distance driving, the replacement interval should be reduced to 70% of the standard mileage. This preventive maintenance can save about 80% of repair costs. Other filters, such as a clogged air filter, will result in insufficient air intake, and issues with the fuel filter may cause fuel injector blockage. All filters need to be replaced periodically as specified in the manual to maintain optimal vehicle performance.