Why Does Fuel Consumption Increase Right After an Oil Change?
2 Answers
An increase in fuel consumption right after an oil change is a normal phenomenon. Here is an explanation regarding the increase in fuel consumption after an oil change: 1. Normal situation: During maintenance, the vehicle's onboard computer may be upgraded, which resets the average fuel consumption. Additionally, vehicles often undergo short-distance movements during maintenance, and after replacing the oil and oil filter, the engine may idle for a period, both of which can slightly increase fuel consumption. 2. Special circumstances: (1) Increased fuel consumption due to overfilling of oil during maintenance. If there is too much oil, the crankshaft may be submerged in it, increasing resistance and naturally raising the engine's load. In some vehicles, fuel consumption may even double. Moreover, excessive oil can increase the burden on the piston rings to scrape off oil, potentially leading to blue smoke from the exhaust. (2) Increased fuel consumption due to loose spark plugs. Leakage from improperly tightened spark plugs can cause the engine to lose power, unstable idling, stalling at high speeds, increased fuel consumption, or even prevent the engine from starting. In severe cases, it can lead to spark plug failure or engine damage.
I remember after changing the engine oil myself last time, I felt the car's fuel consumption suddenly increased a bit, and it didn't run as smoothly. This might be because I used high-viscosity oil. If the viscosity is too high, it increases friction during engine operation, reducing combustion efficiency and naturally increasing fuel consumption. Additionally, if not careful during maintenance, overfilling the oil beyond the upper limit means the engine has to overcome more resistance when running, which also raises fuel consumption. Right after changing to new oil, engine components need some time to adapt to the new lubrication environment, just like new shoes need breaking in. It's advisable to drive a couple hundred kilometers first to observe. If fuel consumption remains high, check the dipstick to confirm the oil level and whether the type is correct. The oil type should be selected according to the manual; for example, choosing thinner oil in summer can help save fuel. Never overlook this, as long-term neglect can damage the engine, and higher fuel consumption means spending more on gas. Regular maintenance is a good habit, but make sure it's done correctly.
