Filling up a car’s tank is becoming more and more expensive because fuel prices are reaching record highs in many countries.
We have analyzed five tricks commonly used by drivers to save fuel. Which ones work and which ones are pure myths?
1) Is 90km/h the best speed to optimize fuel?
Many drivers consider driving at exactly 90km/h to be the most fuel-efficient way to optimize fuel.
However, there is no fixed ideal driving speed, according to the automotive group RAC.
The 90km/h myth, they claim, arose from old fuel consumption tests, which were conducted at three speeds: in town, at 90km/h and at 120km/h.
The most efficient of the three was 90km/h, which led many to believe that this was always the best speed.
However, depending on the type of car and its size, the RAC claims that 70 to 80km/h is most efficient.
2) Should I turn off the air conditioning?
If you’ve ever resisted the temptation to run the air conditioning on a hot summer day to save fuel, you did well.
It takes extra energy to run a car’s air conditioning system and turning it on can increase fuel consumption by up to 10% according to the AA.
The impact can be more noticeable on shorter journeys. That’s because the air conditioner has to use more energy initially to lower the interior temperature of the car.
Opening the windows might be better, but this creates another problem called “drag”. This is where the engine has to work harder to compensate for the air resistance created by the open windows.
If there is a choice between the two, the better option will depend on speed. Air conditioning is probably best above 50 mph because the faster you drive, the greater the drag caused by open windows.
3) Does driving in neutral save fuel?
Inertia driving is driving with the car in neutral or with the clutch pedal depressed.
The AA Automobile Association does not recommend it. Not only could it be unsafe (because you might not be able to accelerate out of a sticky situation), but it’s unlikely to save you gas.
According to the AA, most cars have electrical controls that cut off the fuel supply whenever you lift your foot off the accelerator, so there’s nothing to be gained by coasting.
4) Does cruise control save fuel?
Cruise control, a device that keeps the car at a constant speed without having to use the accelerator pedal, is often considered a sure-fire way to save fuel, as it avoids unnecessary acceleration and hard braking.
However, this may only be true when driving on the freeway, because it is a constant flat surface.
On other types of roads, you are more likely to encounter gradients, so it will take time for the cruise control to adapt to the change in gradient, consuming more fuel in the process.
Typically, you would lift your foot off the accelerator when you start to descend a hill. But because the cruise control can’t see what’s ahead, it spends more time using energy, leading to worse fuel consumption.
5) Does incorrect tire pressure consume more gasoline?
Underinflated tires consume more gasoline. The advice is to check your tire pressure regularly, especially before embarking on a long trip.
Your car’s manual will tell you what the correct pressure is, but you may need to increase it to the recommended maximum if you are carrying several passengers and heavy luggage.
However, any extra weight will still consume more fuel, so skip anything you don’t need.