With petrol prices staying stubbornly high across New Zealand in 2026, more Auckland drivers are asking the same question: why does my car seem to be drinking more fuel than it used to? The answer, more often than not, comes down to maintenance — or the lack of it.
At Tony Allen Auto Service in Manukau, we’ve been working on vehicles since 1985. Over those four decades, one thing has stayed consistent: a properly serviced car uses significantly less fuel than one that’s been left to run on. That’s not a sales pitch. It’s physics.
This guide covers the specific mechanical issues that drive up fuel consumption, what our technicians check during a service, and what local Auckland drivers — and fleet operators — can do right now to bring running costs down.
By the Numbers
Why Servicing Directly Affects Fuel Use
Your engine is designed to operate within tight tolerances. When components wear, drift out of specification, or become contaminated, the engine has to work harder to produce the same output — and working harder means burning more fuel.
A New Zealand Energy Efficiency and Conservation Authority (EECA) study confirmed that a well-maintained vehicle uses 10 to 20 percent less fuel than a poorly maintained equivalent. For the average Auckland driver covering 15,000 km per year, that’s a meaningful saving at the pump every time you fill up.
The Six Areas We Check for Fuel Efficiency
1. Oxygen Sensors
The oxygen sensor tells your engine’s ECU how much fuel to inject. When it fails or reads inaccurately, the engine often runs rich — injecting more fuel than the combustion process actually requires. A faulty sensor can reduce fuel economy by as much as 40 percent. Our technicians carry out a scan tool inspection and sensor function test as part of a full diagnostic service.
2. Air and Fuel Filters
A clogged air filter restricts the airflow your engine needs to burn fuel efficiently. A dirty fuel filter forces the fuel pump to work harder and can cause uneven fuel delivery. Both are straightforward replacements during a scheduled service and have a direct impact on economy and performance. We replace these to manufacturer-specified intervals.
3. Spark Plugs
Worn or fouled spark plugs produce an incomplete burn. When combustion isn’t clean, you lose power and efficiency simultaneously. Replacing spark plugs at the correct service interval restores the combustion cycle to specification and eliminates the fuel waste that comes with misfires.
4. Wheel Alignment
Misaligned wheels create rolling resistance — your tyres are effectively fighting each other as the vehicle moves forward. That resistance costs fuel on every trip. Correct wheel alignment reduces tyre wear, improves handling, and reduces load on the drivetrain. Our alignment equipment handles everything from passenger vehicles through to light commercial trucks.
5. Tyre Pressure
Under-inflated tyres are one of the most common and most overlooked fuel wasters on New Zealand roads. A soft tyre has a larger contact patch and greater rolling resistance, so the engine works harder to maintain speed. Keeping tyres at the correct pressure — which we check and set at every service — can improve fuel efficiency by 10 to 12 percent.
6. Engine Oil Grade and Condition
Old, degraded oil increases internal friction. So does using the wrong viscosity grade for your engine. We use manufacturer-specified oil grades and change intervals to ensure your engine runs with correct lubrication — keeping friction losses to a minimum and protecting long-term engine health at the same time.
“Regular maintenance can make a big difference to your vehicle’s safety, lifespan and fuel efficiency — a well-maintained vehicle uses 10–20% less fuel than a poorly maintained one.”
— EECA (Energy Efficiency and Conservation Authority, New Zealand)
What a Fuel-Focused Service at TAAS Includes
When you bring your vehicle into our Manukau workshop for a service, here’s what we check with fuel efficiency in mind:
- Scan tool diagnostic — fault codes, sensor readings, live data
- Oxygen sensor function test
- Air filter inspection and replacement if required
- Fuel filter inspection and replacement if required
- Spark plug condition assessment and replacement to schedule
- Engine oil drain, filter change, and correct-grade refill (Castrol Magnatec 5W-30 standard)
- Tyre pressure check and inflation to door-placard specification
- Tyre tread depth measurement — flagging anything under 3mm
- Four-wheel alignment check — measured, not a visual estimate
- Coolant and throttle body inspection for economy-affecting faults
- Written technician report with recommended follow-up work
For Fleet Operators in South Auckland
If you’re running a fleet out of Manukau, East Tamaki, Wiri, Papakura, or anywhere across South Auckland, fuel is almost certainly in your top three operating costs. A vehicle that’s 15 percent less efficient than it should be doesn’t look dramatic on a single invoice — but across a fleet of eight or ten vehicles running daily, it accumulates into a substantial budget problem by the end of a quarter.
TAAS works with commercial clients on scheduled fleet maintenance programmes. We coordinate servicing around your operational requirements, provide consolidated reporting, and flag fuel-efficiency issues as a standing item in technician reports. If reducing fleet running costs is a priority for your business in 2026, contact us to discuss a fleet service arrangement.
Simple Habits That Compound the Savings
Servicing does most of the mechanical work, but driving habits also make a measurable difference. Reducing motorway speed from 100 km/h to 90 km/h can lower fuel use by approximately 10 to 15 percent. Avoiding heavy acceleration into intersections, planning routes to minimise cold starts, and removing unused roof racks or tow bars when not in use all add up to real savings on top of what a service delivers.
When Was Your Vehicle Last Serviced?
If you can’t remember, that’s often the answer. Most passenger vehicles benefit from a service every 10,000 to 15,000 km or every twelve months — whichever comes first. Many light commercial vehicles require more frequent attention depending on load and operating conditions.
If your car is feeling sluggish, your fuel receipts are climbing, or it’s simply been a while since anyone looked at it properly, bring it into the workshop at 139 Cavendish Drive, Manukau. We’ll inspect it, tell you what we find, and give you a clear picture of what’s worth doing and why.
No pressure. Just straight workshop advice — the way we’ve operated since 1985.
Book a Fuel Efficiency Service
Serving Manukau · Papatoetoe · Wiri · East Tamaki · Papakura · South Auckland
Call 0800 100 876Visit taas.co.nz139 Cavendish Drive, Manukau, Auckland · Est. 1985 · MTA Assured
