In 2015, two men embarked on a remarkable journey across the continental United States in a Volkswagen, using just over 100 gallons of fuel. Their 81-mile-per-gallon performance doubled the car’s estimated fuel rating and set a record for the lowest fuel consumption ride of a diesel car. The duo, known as hypermilers, are experts in techniques that maximize a car’s fuel efficiency, such as the pulse-and-glide.
In the pulse-and-glide technique, drivers slowly accelerate until they’re traveling slightly above their intended speed. They then slowly release the throttle and glide until they’re slightly below their intended speed, and repeat the process. This strategy saves fuel by optimizing the internal combustion engine’s (ICE) performance.
Non-electric cars run on ICEs, which are often advertised as having a 4-, 6-, or 8-cylinder engine. Within each of these cylinders is a piston that moves up and down, spinning a bar known as a crankshaft, effectively converting linear motion into rotary motion that can drive the wheels. The pistons’ movements are powered by combustion, which occurs when air and fuel are sprayed into the cylinder’s chamber and then compressed. In gasoline engines, a spark ignites the gas, while in diesel engines, the compression alone creates a mini explosion.
The pulse-and-glide technique can increase efficiency for two reasons. First, when accelerating to higher speeds during the pulse, the engine works at a higher efficiency compared to traveling at a constant lower speed. Second, modern car engines shut off fuel injection or idle when decelerating. This means that as the car glides, the wheels are driven by inertial energy, rather than combustion, ultimately saving fuel.
Despite the impressive performance of ICE hypermilers, they can’t compete with the true champion of fuel efficiency: the electric vehicle (EV). EVs run on induction motors, which have two main parts: a stator and a rotor. By conducting electricity at variable rates, these wires create a rotating magnetic field, causing the rotor to spin and drive the motion of the wheels. EVs utilize battery power rather than gasoline, meaning 65 to 69% of the energy consumed by EVs goes directly to moving the wheels.
EVs are completely changing the hypermiling game as drivers compete to travel the farthest on the fewest kilowatt-hours. The design of EV motors allows for the introduction of innovative energy-saving devices, such as regenerative braking and rooftop solar panels. Regenerative braking conserves energy normally lost to friction by capturing the vehicle’s kinetic energy to recharge the battery. Rooftop solar panels further increase the range of EVs.
Since they don’t burn fuel, EVs have zero tailpipe emissions. However, they require regular charging of their batteries, meaning their emission profile is only as clean as the electric utility they plug into. As global grids continue to shift towards renewable sources, EVs are also becoming greener, making them an even more attractive, hyper-efficient option.
Create a simple driving simulation game where you can practice the pulse-and-glide technique. The game should allow you to accelerate and decelerate, showing how fuel efficiency changes with different driving styles. This will help you understand the practical application of the technique.
Using simple materials like cardboard, straws, and rubber bands, build a working model of an internal combustion engine. This hands-on activity will help you visualize how pistons, crankshafts, and combustion work together to power a car.
Calculate the fuel efficiency of different vehicles using real-world data. Compare the results of traditional ICE vehicles with those of electric vehicles. This exercise will help you understand the differences in energy consumption and efficiency between the two types of vehicles.
Participate in a classroom debate on the future of transportation. One side will argue for the continued use of ICE vehicles with improved hypermiling techniques, while the other side will advocate for the adoption of electric vehicles. This will help you develop critical thinking and public speaking skills while exploring the pros and cons of each technology.
Work in groups to design a concept for a sustainable vehicle that incorporates both hypermiling techniques and modern EV technologies like regenerative braking and solar panels. Present your design to the class, explaining how it maximizes fuel efficiency and minimizes environmental impact.
record-breaking – setting or breaking a record – The athlete’s record-breaking performance left the crowd in awe.
fuel efficiency – the measure of how effectively a vehicle uses fuel – The hybrid car boasts impressive fuel efficiency, consuming less gas than its competitors.
journey – the act of traveling from one place to another – We embarked on a long journey across the country, enjoying the scenic views along the way.
hypermilers – individuals who strive to maximize fuel efficiency in their vehicles – The group of hypermilers organized a workshop to share tips and techniques for saving fuel.
pulse-and-glide – a driving technique that involves alternating between accelerating and coasting – The hypermilers practiced the pulse-and-glide technique to optimize their fuel consumption on the highway.
internal combustion engine – a type of engine that generates power by burning fuel within the engine – Most traditional cars are equipped with an internal combustion engine that relies on gasoline for propulsion.
increasing efficiency – improving the effectiveness or productivity of a process or system – The company implemented new strategies to enhance production efficiency and reduce waste.
electric vehicles – automobiles that are powered by electricity rather than fossil fuels – The rising popularity of electric vehicles is contributing to a greener and more sustainable transportation system.
revolutionizing hypermiling – bringing about a significant and transformative change in hypermiling practices – The innovative device revolutionized hypermiling by providing real-time feedback on fuel consumption and driving habits.
environmental impact – the effect that human activities have on the natural world and ecosystems – The construction of the new eco-friendly building aimed to minimize its environmental impact by utilizing sustainable materials and energy-efficient systems.
