After replacing with new engine oil, the vehicle's operating condition does improve, but the perceived increase in power is more of a subjective feeling rather than an actual performance enhancement. New engine oil can reduce internal friction resistance in the engine, making its operation smoother, especially excelling in cleanliness, heat dissipation, and vibration damping, which can create the illusion for drivers that "acceleration feels quicker." In reality, when the engine oil reaches its optimal working state after 3,000 to 4,000 kilometres of use, its lubrication efficiency and fuel economy are actually superior to those of brand-new engine oil. If the viscosity of the replacement oil is significantly lower than that of the old oil, the reduced engine friction will result in a more responsive driving feel, but actual measured power output typically varies by no more than 4%. It is advisable to select manufacturer-approved genuine engine oil and adhere to regular change intervals, as this practice is essential for sustaining long-term engine health rather than chasing temporary power gains.
