Why Is My Car Using More Fuel Than Usual? Common Causes of Poor Fuel Economy
Is your car using more fuel than usual?
If you’re filling up more often even though your driving habits haven’t changed, your car may be using more fuel than it should.
A sudden or gradual drop in fuel economy can have several causes. Some are relatively simple, such as low tyre pressure, while others can point to a mechanical problem that needs attention.
Here are some common reasons your car might be using more fuel than usual.
1. Your Tyre Pressure Is Too Low
Underinflated tyres create more rolling resistance, which means your engine has to work harder to keep the vehicle moving.
Even if your tyres don’t look noticeably flat, incorrect pressure can affect fuel economy and contribute to uneven tyre wear.
Check your tyre pressure regularly and follow the manufacturer’s recommended pressure for your vehicle.
2. Your Air Filter Is Dirty
Your engine needs a steady supply of air to operate efficiently. An excessively dirty or clogged engine air filter can restrict airflow and may affect engine performance.
Air filters are generally inspected as part of routine servicing and replaced when necessary.
If it has been a while since your last service, having the filter checked is a simple place to start.
3. Your Spark Plugs Are Worn
In petrol engines, spark plugs ignite the air-fuel mixture inside the engine.
Worn or faulty spark plugs can contribute to poor combustion, which may lead to reduced performance, rough running, starting problems, or increased fuel consumption.
Spark plugs have recommended replacement intervals, although the exact timing depends on the vehicle and type of spark plug used.
4. There’s a Problem With a Sensor
Modern cars rely on numerous sensors to manage engine performance and fuel delivery.
If a sensor begins sending incorrect information to the engine management system, the vehicle may use more fuel than necessary. Depending on the fault, you might also notice reduced performance, rough idling, or a warning light on the dashboard.
Diagnostic testing can help identify whether an electronic or sensor-related problem is contributing to poor fuel economy.
5. Your Wheels Are Out of Alignment
Poor wheel alignment doesn’t just affect handling and tyre wear. It can also make your vehicle work harder to move efficiently.
Signs of an alignment problem can include uneven tyre wear, the car pulling to one side, or a steering wheel that doesn’t sit straight when you’re driving on a level road.
If you’ve recently hit a pothole or kerb or have noticed changes in the way the vehicle handles, it’s worth having the tyres, wheels, and alignment checked.
6. You’re Carrying More Weight Than Usual
The heavier your vehicle is, the more energy it requires to move.
Keeping unnecessary heavy items in the boot or regularly carrying extra equipment can increase fuel consumption. Roof racks and other external accessories may also increase aerodynamic drag, particularly at higher speeds.
If your fuel usage has increased, consider whether the way you use or load the vehicle has changed.
7. Your Driving Conditions Have Changed
Not every change in fuel economy means there’s something wrong with the car.
Heavy traffic, frequent short trips, extended idling, stop-start driving, and increased use of air conditioning can all affect fuel consumption.
This can be particularly noticeable during hot Gold Coast weather when your car’s air conditioning is working hard on most trips.
If your driving conditions haven’t changed but your fuel consumption has, however, there may be another cause worth investigating.
8. Your Car Is Overdue for a Service
Regular servicing helps keep the systems that affect engine performance and efficiency in good working order.
Old engine oil, worn components, dirty filters, ignition problems, and other maintenance issues can contribute to poor performance and increased fuel consumption.
Following your vehicle manufacturer’s recommended servicing schedule can help identify these issues before they develop into larger problems.
How Do You Know If Your Car Is Using More Fuel Than Usual?
Fuel economy naturally varies depending on traffic, driving style, vehicle load, weather, and the type of trips you take.
What matters most is a noticeable change from what’s normal for your vehicle.
If you’re suddenly filling the tank more frequently without an obvious reason, keep track of your fuel consumption over several trips. A consistent increase can be a useful sign that the vehicle should be checked.
Get Poor Fuel Economy Checked
Higher fuel consumption can cost you at the pump, but it can also be an early sign that something in your vehicle needs attention.
Bentley Auto Repairs provides car servicing, diagnostics, and mechanical repairs for Gold Coast drivers. If your vehicle is using more fuel than usual or isn’t running the way it normally does, our team can inspect it and help identify the cause.
Noticing a drop in your car’s fuel economy? Contact Bentley Auto Repairs to book a service or inspection.
