Why Does Fuel Consumption Increase Right After an Oil Change?

[AuroraLee]

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.