Will a Car Consume More Fuel Without Maintenance?

[TuckerLynn]

Failure to maintain a car can lead to increased fuel consumption. Below are the specific impacts of prolonged lack of maintenance: Compromises Driving Safety: As engine oil comes into contact with air and is exposed to heat, it gradually oxidizes. Over time, the oil accumulates acidic substances, sludge, and metal particles, causing it to darken and lose viscosity. Prolonged failure to change the oil may lead to clogged oil passages, resulting in dry friction within the engine and severely shortening its lifespan. Risk of Smoke and Fire: The cooling efficiency of the coolant diminishes, leading to the formation of scale. If the engine continues to operate at high temperatures, it may emit smoke or even catch fire.

[Francisco]

Last time my friend's car fuel consumption soared to 13 liters per 100km. When I checked for him, I found out he hadn't changed the engine oil for three years - it was as thick as syrup. When engine oil deteriorates, the engine has to work extra hard, and fuel can't burn completely, so it guzzles gas like water. An air filter clogged like a rag also restricts airflow, causing the ECU to inject more fuel to compensate. The most shocking part was the tire pressure - all four tires were only at 1.8 bar, creating terrifying friction with the road. Actually, the maintenance manual's recommendation to change oil every 5,000km isn't a scam. I've personally seen spark plugs with completely worn electrodes from lack of replacement, causing half-second ignition delays where every press of the accelerator wasted gasoline.

[MaciFitz]

Ladies, let me share a painful lesson! Last year, I neglected maintenance, and my refueling frequency went from once every two weeks to once every ten days. The mechanic said my air filter was clogged with willow catkins, and the engine couldn't breathe—like running with an N95 mask on, requiring deeper throttle presses. He also found severe carbon buildup on the spark plugs, with sparks as weak as a lighter running out of battery, causing unburned fuel to be expelled. The worst part? The oxygen sensor was coated in carbon, tricking the ECU into thinking the mixture was too lean, leading to excessive fuel injection—no wonder my tank felt like it had a hole.

[DeRobert]

From a mechanical perspective, lack of maintenance directly disrupts the air-fuel ratio balance. Taking a common example: engine oil overdue by 10,000 kilometers experiences a 40% viscosity index degradation, resulting in an 18% increase in crankshaft operating resistance. When combined with an air filter clogging rate exceeding 80%, insufficient air intake forces the ECU to increase fuel injection pulse width by 22%. With aging spark plugs causing a 3-millisecond ignition delay, combustion chamber temperature drops by 200°C, leading to a 15% surge in unburned hydrocarbon emissions. These factors translate to fuel consumption, increasing it by at least 1.8 liters per 100 kilometers under combined driving conditions.

[VanKayden]

Maintenance is linked to three major risks: First, the wallet crisis. Actual tests show that vehicles overdue for maintenance generally experience a 15%-30% increase in fuel consumption. A colleague's SUV, which didn't have its transmission fluid changed, saw its engine speed inexplicably surge due to torque converter slippage, consuming 19 liters per 100 km in city driving. Second, safety hazards. I've witnessed cases where long-term neglect of brake fluid changes led to caliper seizure, with wheel hubs heating up enough to ignite tire pressure sensors. Most critically, the impact on used car resale value. Dealers directly slash prices by 20,000 yuan for cars with blank maintenance records, equating it to slow suicide for the vehicle.