Why is my car using so much fuel?

Many drivers notice that fuel consumption suddenly goes up by 1–3 l/100 km, and their wallet gets thinner faster than usual. High consumption isn’t just an unpleasant surprise at the pump—it’s often a sign your car needs attention. Let’s look at the most common causes and simple steps to fix them. You can also upgrade your vehicle and make it more efficient by using tuning accessories, with a wide selection available in our online store.

Driving and operating factors

1. Aggressive driving style: Hard launches, sharp braking, and driving at high RPM increase consumption by 20–40%. Smooth acceleration and engine braking help save fuel.
2. A/C on or windows open: Air conditioning adds 0.5–1.5 l/100 km, while open windows at speeds over 80 km/h hurt aerodynamics.
3. Low tire pressure or extra load: Underinflated tires increase rolling resistance by 5–10%. A roof rack or unnecessary items in the trunk also “eat up” fuel.
4. Traffic jams, short trips, and winter conditions: Frequent warm-ups, stop-and-go traffic, and a cold engine are classic “fuel guzzlers” for both gasoline and diesel.

Technical issues that increase fuel consumption

1. Clogged filters (air and fuel): A dirty air filter forces a richer mixture—consumption rises by 5–15%.
2. Faulty thermostat: The engine doesn’t reach operating temperature, so the ECU injects more fuel. Consumption can increase by 10–20%.
3. Fuel system problems: Worn injectors, leaky intake hoses, or a faulty MAF sensor/oxygen sensor can cause overfueling.
4. Poor-quality fuel or engine oil: Bad gasoline/diesel or old high-viscosity oil increases friction and worsens combustion.

What can you do to reduce consumption right now?

• Check tire pressure (monthly).
• Replace the air and fuel filters.
• Switch to a smoother driving style.
• Turn off the A/C when it’s not hot.
• Run an ECU diagnostic and check the spark plugs/injectors.

Fixing the causes in time will bring consumption back to normal and save you money.