Car symptom
High fuel consumption
A sudden jump in consumption usually has a physical cause; a gradual rise is often maintenance.
Most likely causes
- Dragging brake caliper
- Oxygen sensor failing
- Under-inflated tires
- Dirty MAF or air filter
- Thermostat stuck open
Checks to run
- Check tire pressures
- Feel each wheel for drag
- Read fuel trims
- Check coolant temperature
Tools you may need
Tire gauge
OBD-II scanner
Confirm before replacing. These are hypotheses to check — never buy parts on a guess. If the fault involves brakes, airbags or fuel under pressure, use a professional.
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FAQ
It depends on the cause. Some causes are cheap and quick; others (like a head gasket or seized caliper) need attention soon. Work through the checks in order and confirm before replacing parts.
Start with the free checks listed here. If they involve high voltage, fuel under pressure, airbags or brakes, let a professional handle it.
The interactive diagnostic asks targeted questions to narrow it down, and every cause must be confirmed with a measurement — never guess.