With fuel prices doing their usual unpredictable dance at the bowser, most drivers in Leichhardt and Marrickville are already wincing at fill-up time. What many don’t realise, though, is that their car might be actively making things worse. A number of common mechanical issues cause your engine to work harder than it needs to — burning more fuel without you ever knowing why your tank seems to empty faster than it used to. Here are five culprits worth knowing about.
1. Underinflated tyres
This is one of the most widespread and easily overlooked fuel wasters. When tyre pressure drops below the recommended level, the contact area between tyre and road increases, creating more rolling resistance. Your engine compensates by using more fuel. The fix is simple and free — check your tyre pressure regularly — but without routine maintenance, it’s the kind of thing that quietly costs you money for months.
2. A dirty or clogged air filter
Your engine needs a precise mix of fuel and air to run efficiently. A clogged air filter restricts airflow, forcing the engine to compensate in ways that increase fuel consumption. Air filters are inexpensive to replace and are typically checked during a standard service — but if you’ve been stretching the gap between services, this could easily be working against you.
3. Worn spark plugs
Spark plugs ignite the fuel-air mixture in your engine’s cylinders. When they’re worn or fouled, combustion becomes incomplete and inefficient. The engine fires less cleanly, wastes fuel and may also run roughly or hesitate under acceleration. Replacing spark plugs at the recommended intervals is a small investment that pays for itself in improved efficiency and engine health.
4. A faulty oxygen sensor
Your car’s oxygen sensor monitors exhaust gases and helps regulate the fuel-air mixture in real time. When it fails or degrades, the engine management system loses accurate feedback and often defaults to running rich — meaning too much fuel. A faulty oxygen sensor can increase fuel consumption noticeably, and because it doesn’t always trigger obvious symptoms, it can go undetected without a proper diagnostic check.
5. Old or incorrect engine oil
Engine oil reduces friction between moving parts. When it degrades, thickens, or isn’t the right viscosity for your engine, internal friction increases and the engine works harder. Using the manufacturer-recommended oil and changing it on schedule makes a genuine difference to both efficiency and longevity.
For Leichhardt and Marrickville drivers, the common thread here is straightforward: most of these problems are entirely preventable with regular, quality auto maintenance. A trusted local mechanic who knows your vehicle isn’t just keeping it roadworthy — they’re quietly saving you money every time you fill up.
