2025 ASE Auto Maintenance & Light Repair (G1) Complete Practice Test

Engine oil should typically be changed every 3,000 to 5,000 miles because this range helps maintain optimal engine performance and prevents damage due to oil degradation. Oil plays a critical role in lubricating engine components, reducing friction, and facilitating heat dissipation. Over time, oil can become contaminated with dirt, debris, and combustion byproducts, which can compromise its effectiveness.

Following the recommended change interval ensures that the oil retains its ability to protect the engine, as well as optimize fuel economy and performance. Some manufacturers now suggest longer intervals based on advancements in oil technology and engine design; however, many still recommend the 3,000 to 5,000-mile range as a safe standard, especially for older vehicles or those with specific operating conditions.

Other options may not provide adequate maintenance for the engine. For instance, waiting until oil appears dirty does not prevent potential engine wear that could occur if the oil becomes too degraded before changing. Changing oil once a year may not be frequent enough given driving habits and environmental factors, and relying on a mileage of 10,000 miles without considering other factors could risk overextending the oil's effectiveness and lead to engine problems.