Driving can be great. Many of us have to do it to commute or as part of our daily work duties. Others drive just for recreational purposes. Whichever driver you are, you are likely to want to know how to dive in the most economical way.
Firstly, we must emphasize that driving within the applicable laws in your location is essential. Also, safety is paramount at all times. Never do anything that may jeopardize yourself, others or any property. The following information can be tried one step at a time, in a safe, controlled and deserted area to see if you can improve your mile per gallon (or liters per 100 kilometers depending on the unit of measure that you prefer to use). Always drive within all legal parameters applicable to your circumstances. Always ensure that your car is correctly maintained and suitable for purpose.
The first thing to keep in mind is that the more times you need to press a pedal and the more that the pedal needs to be pressed, the more money you are using. This is true with the break as well as accelerator and partially true in relation to the clutch in certain circumstances.
Hard acceleration i.e. when the accelerator is pressed more than a small amount, will make the engine rev higher and allow more fuel to be delivered to the combustion chamber in the cylinder of your engine. Also, in many vehicles, this may mean that more fuel is delivered than the air/fuel mixture allows for maximum combustion efficiency. Keeping the fuel and air mixture near to the maximum for fuel combustion efficiency is better for economical driving. Therefore, never accelerate hard unless the road conditions or circumstances require you to do so (again, safety is key). Try to get into a suitable higher gear as soon as possible when driving. Please note that the word suitable is used here. The engine must be at suitable revs for the gear selected, at the road speed that you are travelling. If the engine is revving too low and there is a significant force for the engine to counter (e.g. too higher gear selected or you are going up hill, or there is a large amount of rolling resistance from the surface of the road), the engine will be nearer the engine idle revs and will be closer to stalling. When the engine is nearing revs that are too low for the gear selected, more fuel will be needed to stop the engine from stalling – in this situation a lower gear, with less accelerator depression may be preferable. An element of trial and error may be needed with your particular vehicle. If you have a modern car, they may be an onboard computer that gives indication of your current fuel economy. Diesel and petrol engines behave differently as do modern fuel injected systems and more traditional carburettor equipped engines. Engines with turbos also behave differently because the turbo system may reduce air flow at lower revs and then increase it significantly at higher revs once the turbine in the ‘turbo’ begins to spin. Please use a search engine to look at how a turbo system works. Please note that diesel and petrol turbo systems have their differences. A ‘rev’ is a revolution i.e. one full turn. The rev is usually one complete 360 degree turn of the crank shaft at the bottom of the engine (nothing to do with a wheel turn, which is affected by several factors such as the gearing of the cars gearbox and drivetrain etc.). Please search the internet for more information on this if you require it.
Braking when not necessary is potentially another cause of fuel wastage. Of course, brakes need to be used to stop and brakes should be applied when needed to ensure safety. However, when on faster, straight, single direction roads such as motorways (highways, autobahns etc.) braking may be a result of poor driving in the first place. If you read and judge the road conditions and speed of the traffic in front of you, you may be able to apply your brake less frequently, in a more gentle and controlled manner. People who drive too quickly for the traffic conditions or drive too closely to the person in front are probably using more fuel than is necessary at the acceleration stage and braking more than is necessary at the deceleration stage (as well as potentially being unsafe). You may be reading this and thinking ‘why do I care about the economics of braking when brake pads and discs are comparatively cheap in relation to my other motoring costs’. Now, this is where you need to think outside the box. Braking too harshly, or when braking could have been avoided by more sensible (and safe) driving in the first place, means that costs mount in two ways. The first cost is the direct result of braking, which causes excessive wear to the brake parts and tyres. The second cost is due to lost momentum and inertia. Most fuel is used getting up to speed per unit of time driven. This is because the accelerator is pressed further to get to the speed desired (the inefficiency of this has been previously explained). The moment that the brake is applied, the car slows down. This means that the energy from the fuel used to get to the speed you were travelling at has now been lost. To get back to the higher speed, you would burn more fuel per unit of distance than maintaining a slightly lower speed (as long as the engine was operating in its efficient zone of speed, resistance and revs). The lost energy and reduced momentum of the car is what causes inefficiency in terms of monetary costs, way in excess of the costs related to the physical components (parts) involved in the braking system. Brake when needed to be safe. Less aggressive acceleration may lead to less unnecessary braking. Think throughout your whole journey and drive safely, legally and economically.
Once you have mastered safe, economical acceleration and braking, it is time to make sure that your car is prepared for fuel economy. One of the most common things that people do to unnecessary increase the fuel consumption during each journey is have the car laden with heavy and unnecessary objects. For example, if you play golf twice a week, put the clubs in the car twice a week and store them at home when they are not required. A large set of clubs with a bag and trolley can weigh as much as an extra person on board, if not more. The car’s engine has to move this extra weight, which causes unwanted usage of additional fuel. Ensure that your car is not full of unnecessary objects.
Ensure that your car is serviced correctly. Clean oil and renewed filters mean that the engine can function more smoothly and that the engine management systems can make the fuel system work in an efficient manner as the manufacturer intended. Not all vehicles have electric engine management systems (controlled by an engine control unit), but most modern cars do. Even those without an engine control unit (ECU) may function more efficiently with the correct grade of clean oil and filters (including oil, air and fuel) that are not blocked, damaged or past their best.
The last section of this article related to steering. The more movement of the steering wheel, the more that the tyres have to turn in a direction against the direction of travel. This turning means that the tyres ‘scrub’ speed because they are actually causing increased friction with the road surface when in a turned state. Increased friction causes increased rolling resistance and has a similar effect to braking on the cars momentum and overall efficiency of travel. Obviously, you need to turn corners, but refrain from turning/moving the wheel even slightly when on straight roads. Also, slow for corners so that swift steering wheel movements are not required. Slowing for corners is also safer as it means there is less chance of loss of control, especially if the road surface has any slippery debris. Do not over-brake into corners, instead judge the corners and let the car slow naturally (keeping the car in gear for safety) when approaching the corner. Apply the brake as needed and gently when possible.
We hope that you have found this information useful. Always drive legally and safely. If in doubt ask a suitable professional for their advice. Never drive in dangerous conditions unless absolutely necessary.
Thank you for reading this article. Look after yourself, keep your car correctly maintained and always drive as safely as possible! The owners of this website and any party involved cannot be held responsible for your actions. Do not act without first ensuring that it is safe to do so and legal.