What Causes High Fuel Consumption?

[StJuniper]

High fuel consumption in vehicles is primarily caused by the following factors: abnormal tire pressure or switching to larger-sized tires; prolonged idling without turning off the engine or frequent ignition; aggressive acceleration and frequent braking while driving; driving at high speeds in low gears or low speeds in high gears; fully open windows in summer or using air conditioning during traffic jams; poor route planning, driving on congested roads, and frequent lane changes. Below is a detailed explanation of each cause: Abnormal tire pressure or switching to larger-sized tires: Underinflated tires affect fuel consumption. When tire pressure is too low, the contact area between the tire and the road increases, leading to greater driving resistance and higher vehicle fuel consumption. Prolonged idling without turning off the engine or frequent ignition: During long waits when the vehicle does not need to move, it is recommended to turn off the engine. Every time the engine starts, the computer-controlled fuel injection volume is relatively high, so frequent engine starts within a short period will significantly increase the vehicle's fuel consumption. Aggressive acceleration and frequent braking while driving: Unless absolutely necessary, avoid frequent overtaking while driving. Maintaining a steady speed helps reduce fuel consumption. Additionally, maintaining a proper following distance and minimizing unnecessary braking actions can also save fuel. Driving at high speeds in low gears or low speeds in high gears: This issue is more common among new drivers. Often, the vehicle's speed is already high, but the corresponding gear shift has not occurred, leading to increasingly high engine RPM and naturally soaring fuel consumption. Another scenario is driving at very low speeds while staying in a high gear, which is most noticeably characterized by engine and body vibrations and the risk of stalling at any moment. Fully open windows in summer or using air conditioning during traffic jams: Using air conditioning in summer increases engine load, leading to higher fuel consumption. Poor route planning, driving on congested roads, and frequent lane changes: For this issue, it is recommended to plan the driving route in advance, pay attention to local traffic information and road conditions, and avoid congested routes.

[DeFernando]

Last time when my fuel consumption suddenly increased, I went to check and found that the tire pressure was low, with all four tires being slightly underinflated. This has a significant impact. Insufficient tire pressure increases friction, forcing the engine to work harder to push the tires, which definitely consumes more fuel. Then I checked the oil filter, which was long overdue for a change—it was as sticky as paste. The condition of the engine oil also matters; higher viscosity increases internal engine resistance. After topping up the tire pressure and changing the oil and filter, my highway fuel consumption never exceeded 9 liters per 100 km again. It's also important to develop good habits, like not keeping a bunch of unnecessary items in the trunk, especially heavy ones that just sit there. An extra 100 kg can increase fuel consumption by 1%.

[SanCali]

I've thought a lot about high fuel consumption. First, look at road conditions - frequent stops in traffic mean more acceleration cycles, keeping the engine running at low speeds. Second, driving habits really matter - constant hard acceleration and braking can spike instantaneous fuel consumption over 20L/100km. Air conditioning is another major fuel guzzler, especially in summer city driving where it can increase consumption by 15%. I found cleaning the air filter immediately reduced fuel use since clogged filters restrict airflow causing incomplete combustion. Short commutes are the least fuel-efficient as the engine oil never reaches optimal temperature. I recommend occasional highway runs to clean carbon deposits, which significantly helps lower fuel consumption.

[McTeagan]

Recently, the fuel consumption has increased significantly? First, check if the three-way catalytic converter is clogged. If it's clogged, the exhaust won't flow smoothly, and you'll have to press the accelerator harder due to insufficient power. If the spark plugs are worn or the gap is incorrect, the ignition timing will be delayed, causing incomplete combustion of gasoline and wasting fuel. A dirty throttle body affects air intake, leading to an improper air-fuel ratio. Fuel system leaks are even more critical—my relative had a leaking fuel injector seal for days before noticing. Upgrading to larger rims or wider tires increases friction and fuel consumption. All these issues require a professional inspection at a repair shop.