Which of these 11 fuel-saving myths are true?
More miles for less money is music to the ears. Having said that, many fuel-efficiency tricks that may have worked years ago for older models have outlived their heyday. Which is why our two experts bring you an updated look at the myths and truths of saving fuel.
- Refuelling your car in the morning will get you more fuel than in the afternoon common tip is to fuel up when the air is cool, rather than in the heat of the day. The theory is that the cooler fuel will be denser meaning you get more for your money. But most stations store the fuel underground, so its temperature changes very little, if at all, during a 24-hour stretch. Any extra petrol you get is negligible. BUSTED
- Using premium fuel (a grade higher) will make your car perform better virtually all post-1996 car models in Malaysia have knock sensors. If the octane rating is too low, the computer will roll back the ignition timing a few degrees to compensate. This will reduce peak engine power, and also increase fuel consumption. So, in some sense, this is not all myth. Older cars built before the advent of knock sensors may even sustain engine damage with a lesser grade. As a general rule, always use the type of fuel recommended for your ride. POSSIBLE
- A nearly-full tank prevents fuel evaporation theory that a tank more full than empty will prevent fuel from evaporating inside the tank is off-base. Cars of yesteryear may have allowed gas vapours to escape into the air, but fuel systems in modern vehicles (manufactured in and after 2000) are designed with vapour recovery systems. Some vehicles with pressurised fuel systems even display a check engine light if the gas cap is loose, missing or not properly sealed. BUSTED
- Shifting into neutral gear at stops can save feel this is a myth that applied when engines required carburettors. Today’s vehicles (manufactured in and after 1990’s) have computerized fuel-injection systems that detect if an engine is revving above idle when you ease off the accelerator.
If that happens, the fuel injectors shut off, so gas is no longer injected into the engine, even if the car is still in gear. The only thing you accomplish by constantly shifting in and out of neutral is premature wear on shift components. POSSIBLE (for cars with carburettors)
- Manual-transmission rides get better mileage manual transmissions almost always achieve better mileage because a reasonably skilled driver can control engine revving through efficient shifting.
Having said that, today’s high-tech automatic transmissions (manufactured in and after the 1980s) have gone through a lot of significant improvement and higher efficiency to achieve better mileage, reducing the difference significantly. POSSIBLE
- Fuel mileage drops as vehicles ages. As the vehicle age increases, the engine efficiency will drop gradually. If you keep your vehicle properly maintained and see any repairs needed, you shouldn’t see any noticeable decline in fuel economy. But if you don’t maintain your vehicle, its performance and fuel efficiency will naturally degrade. TRUE
- Driving with windows open hurts fuel economy for city driving, rolling down the windows instead of cranking the air conditioner improves your mileage, but once you’re driving more than 50 miles (80.5km) per hour, the increased drag cancels out any fuel savings. When you’re on the highway, roll those windows up and use the AC instead. POSSIBLE
- A dirty air filter leads to lower mileage back when cars had carburettors, changing your air filter could have helped. Today, the on-board computer injects exactly the amount of petrol your car needs. A small restriction in the airflow does n’t make the engine run too rich. The pleated-paper air filters used today are very large and can hold a lot more dirt before they start to choke the engine. POSSIBLE
- Tyres with low rolling resistance are always a smarter choice lot of attention is paid to a tyre’s rolling resistance, which is how much energy it takes to roll along. The lower the rolling resistance, the better your fuel economy will be.
Maintaining the proper tyre pressure will optimise resistance and real-world performance. Some tyres gain low rolling resistance at the expense of wet-braking performance and tread life a poor trade-off. TRUE
- Smaller cars get better gas mileage than larger onesFuel economy is more about the engine and weight than it is about the size. A large roomy car that weighs less than a small car, or has a hybrid or electric engine, will use less fuel than some smaller cars. BUSTED
- Warming up your car on cold days by letting it idle will help you save fuelLetting your car idle will only waste fuel. In fact, today’scars warm up faster once you get on the road than they would just be idling in the driveway. SO BUSTED