Do you know what it means when the fuel light in your car goes on? Maybe you’ve heard that you get more mileage when you fill your tank in the morning? There was even a rumour that your car would go faster if you put jet fuel in it – sounds exciting, but is it true?
Colin Harding is a senior engineer with the Ford team that designs what a driver sees in the ‘instrument cluster’ where the speedo is. Harding and his team are experts in everything related to mileage, and so they spend a lot of time deliberately trying to make cars run out of fuel.
Here, Harding debunks some of the most common myths associated with fueling your car.
Filling your tank in the morning gets you more mileage
Good try, but no. The theory behind this myth is that petrol expands with heat – which is true – so if it’s cooler, you can fit more of it into your tank. But the fact is fuel is stored in tanks below ground where the rising temperature of the day plays no part in the density of the petrol, so fill up whenever you wish.
Letting your fuel run low is bad for your engine
Nope. “The common misconception here is that if you drive on ‘fumes’, your engine will begin to ingest ‘rubbish’ or sediment-littered fuel from the bottom of the tank. But the fuel tank is designed so that the fuel pickup always sips from the bottom of the tank, meaning it is always able to draw fuel. Contrary to popular belief, when you’re running low the quality of the fuel being used by the engine is no different to when the tank is full.”
Premium fuel makes your non-premium car run better
False. When we pull up to the pump, there are more options than ever; words like power and premium, and enough different oils and lubricants to drive anyone mad. And while it may be more expensive, it isn’t any cleaner or purer than regular fuel.
“While it is less combustible, which benefits powerful performance engines, it won’t benefit the vehicles of most daily drivers as all types of fuel have to meet the same standards.”
My range readings are wrong
Unlikely: while the fuel gauge tells drivers exactly how much fuel is in the tank, range readings are calculated based on longer-term driving patterns.
It’s not always clear where myths come from, how they catch on, or why misconceptions can sometimes become the perceived rule. But now you know that following these myths would not get you to save fuel, but the tips below surely can.
Aggressive driving such as rapid acceleration, speeding and braking can lower your fuel mileage significantly. So accelerate smoothly, brake softer and earlier, and stay in one lane while it’s safe to do so.
Speeding wastes lots of fuel. By driving 90km/h instead of 100km/h, you can improve your fuel efficiency by up to 10-15 percent. Also, aim for a constant speed. Pumping the accelerator sends more fuel into the engine, emptying the tank faster.
Today’s engines don’t need a warm up. Start the car immediately and gently drive away. Don’t leave your car idling. Prolonged idling increases emissions and wastes fuel.
Use cruise control
Activating your cruise control keeps you from mindlessly driving faster and with lower fuel efficiency, maintains a constant speed, and won’t use additional fuel while accelerating. Try to set your cruise control at your vehicle’s most fuel-efficient speed, as long as it’s at or below the legal limit.