The experiment investigated the effects of smart driving practices, called Eco-Drive, on a car’s gas mileage and carbon dioxide emission in city driving. The Eco-Drive practices whose cumulative effect was examined include: accelerating slowly, driving at recommended speed, studying the traffic lights ahead to predict the stops and freewheeling the car to slow down before applying the brakes, and also freewheeling the car on down slopes. The hypothesis was that Eco-Drive practices would increase a vehicle’s gas mileage and reduce its carbon dioxide emission in city driving. The experiment used two gasoline cars, driven in two modes - Normal Driving and Eco-Driving. Since 1996, all cars have been equipped with an On-Board Diagnostics (OBD II) port. An OBD II Bluetooth adapter was connected to this port. An OBD II diagnostic software on an Android tablet, communicating with this adapter, was used to measure each trip’s average gas mileage and carbon dioxide emission. Eco-Drive increased the gas mileage by 31.13% for the first car and by 17.64% for the second car. It reduced the carbon dioxide emission by 30.88% for the first car and by 14.19% for the second car. Eco-Drive reduced the trip time for the first car, but it slightly increased the trip time for the second car, so its effect on trip time is inconclusive. The hypothesis was correct. Eco-Drive increases vehicle’s gas mileage and reduces its carbon dioxide emission. Eco-Drive practices offer great benefits and need to be publicized among the drivers all over the world.
Global warming as well as the depletion of our fossil fuel reserves pose a serious threat to our civilization. The world’s crude oil reserves are expected to be exhausted in 34 years, natural gas in 42 years, and coal in 70 years at the current levels of extraction! 2016 was the earth’s warmest year, and 2015 the second warmest on record. Scientists attribute the extreme weather patterns currently being witnessed such as devastating wildfires all across the Western US and severe hurricanes in the Eastern US to global warming caused by greenhouse gases. With transportation contributing a whopping 34% of the total U.S. CO2 emission, finding ways to reduce vehicles’ CO2 emission has become critical. Is there anything the drivers can do? This inspired my research project that attempted to answer the question:
This question is important is because while advanced cars, like electric and hybrid cars, produce less greenhouse gases, these are currently too expensive. Most drivers in poor and developing countries simply cannot afford to buy them. However, if we give them an alternative where it does not cost them anything at all and where they do not need to sacrifice anything, then there is absolutely no reason why they would not use this alternative to reduce global warming.
Cars usually have a high highway gas mileage and a low city gas mileage. This difference is due to the stop-and-go nature of city driving that leads to a low city gas mileage. Eco-Drive comprises of a set of smart driving practices that attempt to make efficient use of car’s kinetic energy and also reduce the number of stop-and-go situations. The main Eco-Drive practices are:
In these Eco-Drive practices the driver does not need to sacrifice anything like turning off radio, air-conditioning etc.
When a car is started from zero speed, a major fraction of the fuel’s energy is used to accelerate the car to the cruising speed. The car gains kinetic energy. A body in motion tends to stay in motion. Once the car is cruising, only sufficient energy is needed to overcome the air and rolling resistance experienced by it. When the brakes are applied to stop the car, the car's kinetic energy turns into heat in the brakes. Reducing the number of stop and go should reduce energy usage.
The traffic signals in most U.S. cities are synchronized. If a driver has just stopped at a red signal, the traffic control system, in order to minimize the number of stops, tries to turn the next few traffic signals ahead of him green by the time he reaches them, if he drives at the recommended speed. Knowing the order in which the traffic signals turn green enables the driver to make a good judgment about whether or not he will need to stop at a signal.
Whenever the driver drives over bridges, rolling the car on the down slopes will make efficient use of the car’s kinetic energy.
Cars sold in the U.S. after January 1, 1996, are equipped with On-Board Diagnostics (OBD II) port that provides valuable information from several sensors used by the car’s Engine Control Unit (ECU). This information (such as gas mileage and CO2 emission) can be read by using an OBD II adapter that connects to the OBD II port and can be analyzed with an OBD II diagnostic software that communicates via Bluetooth with the OBD II adapter.
Eco-Drive practices are also safe driving practices because they encourage the driver to pay more attention to his surroundings, keep more distance from the car in the front, and avoid sudden accelerations and decelerations of the car as well as unnecessary lane changes.
For each level and trial, we need the same driver, same car, same passengers in the car, same start and end points, same route, same time of the day, and driving done on weekdays only where traffic conditions are similar.
Constants that are beyond our control are the number of red traffic lights, traffic congestion, and weather condition encountered in a trip. We can control these a little by driving at the same time every day and ignoring the data when the trip condition is unusual (for e.g. traffic blocked due to an accident).
As the data graphs in Figure 1 and Figure 2 show, Eco-Driving increased the average gas mileage by 31.13% for the first car and by 17.64% for the second car. It reduced the average CO2 emission by 30.88% for the first car and by 14.19% for the second car.
The effect of Eco-Drive on the gas mileage of each car is shown in Table 1 and presented as a bar graph in Figure 1. The effect of Eco-Drive on the CO2 emission of each car is shown in Table 2 and presented as a bar graph in Figure 2.
Figure 1 shows that Eco-Drive increased the average gas mileage for the first car by an outstanding 31.13%. It increased the average gas mileage for the second car by 17.64% which is also quite significant. For the first car, the average gas mileage during Eco-Drive was 11.50 km/l compared with 8.77 km/l during Normal Driving and it varied within a range of 1.0 km/l. For the second car, the average gas mileage during Eco-Drive was 8.27 km/l compared with 7.03 km/l during Normal Driving and it varied within a range of 1.2 km/l.
Figure 2 shows that Eco-Drive also reduced the average CO2 emission for the first car an astounding 30.88%. It reduced the average CO2 emission for the second car by 14.19% which is still a great success. For the first car, the average CO2 emission during Eco-Drive was 207.07 g/km compared with 299.57 g/km during Normal Driving and varied within a range of 6.1 g/km. For the second car, the average CO2 emission during Eco-Drive was 302 g/km compared with 351.93 g/km during Normal Driving and it varied within a range of 4.8 g/km. The data clearly support the hypothesis that Eco-Drive increases a vehicle’s gas mileage and reduces its carbon dioxide emission.
Table 3 shows the effect of Eco-Drive on the total trip time. Eco-Drive reduced the average trip time for the first car, but it slightly increased the average trip time for the second car, so its effect on trip time is inconclusive.
The purpose of the experiment was to examine the effect of Eco-Drive practices on a vehicle’s gas mileage and CO2 emission while using U.S. roads and traffic system. The major findings were—Eco-Drive increased the gas mileage, and it decreased the CO2 emission for both the cars. Therefore, the hypothesis that Eco-Drive increases the gas mileage and reduces CO2 emission was completely supported.
The benefit of Eco-Drive was outstanding for the first car, 2009 Toyota Camry, in terms of both gas mileage and CO2 emission. Even though the benefit was comparatively lower for the second car, 1997 Honda Accord V6, it was still quite significant and can contribute substantially to California’s goal of reducing greenhouse gas emissions by 30 percent by 2020.
There could be several possible reasons why the first car showed more improvement with Eco-Drive compared to the second car. The first car is a newer model than the second car. It was found to have more rolling (freewheeling) distance than the second car which could be due to its better aerodynamic design resulting in lower drag. Also, the second car was due for its next routine maintenance service which may have affected its performance. There may be rust in the wheel and axle arrangement of the second car, which is quite old, that could be reducing its rolling distance. Lastly, the second car is also a six-cylinder model, while the first one is a four cylinder model, and it is possible that six-cylinder models, that are designed for maneuverability rather than comfort, do not give as much gain in freewheeling as four-cylinder models.
The results prove that Eco-Drive has several advantages. It helps conserve our precious energy reserves by increasing vehicle’s gas mileage, it helps drivers save money (as much as 30¢ on a dollar), and it helps protect our environment by reducing CO2 emission.
Eco-Drive practices can be applied to all types of vehicles. An area of further research is to study the effect of Eco-Drive on other vehicle types like trucks, hybrid vehicles, and electric vehicles. For electric vehicles, Eco-Drive’s effect on vehicle’s driving range can be studied. Since Eco-Drive is almost unheard of among the drivers in the U.S., the most important task is to publicize its benefits among the drivers to help conserve energy and preserve our planet.
Hi, my name is Pranjal Agrawal. I am a sophomore at Evergreen Valley High School in San Jose, California. I am passionate about Math, Physics, and Earth Science. I believe that scientific principles can be applied to solve big problems on Earth like global warming. I was a finalist for the Synopsys Outreach Foundation n+1 prize in 2017 Synopsys Silicon Valley Science and Technology Fair for my research on the effect of precipitation on the earthquake activity in California. In my free time, I like to play chess and try out new songs on piano.
I first got interested in Physics by watching car racing on TV. My curiosity led me to learn about Newton’s laws of motion. Watching devastating wildfires, hurricanes, and flooding prompted me to find ways to reduce global warming. This led me to my current project about the effect of eco-driving techniques on gas mileage and CO2 emission of ordinary cars.
My sources of inspiration are the countless scientists and engineers around the world who work on solving cutting-edge, real world problems everyday. One scientist that I particularly admire is Sir Isaac Newton who was the first one to express the principles of Physics in the language of Math.
I want to pursue my passion for science and engineering in college and beyond that in career. I believe that winning the Google Science Fair would provide me with a platform to promote the use of eco-driving techniques around the world to reduce global warming.
The project did not involve risk of any kind.
Eco-Drive practices also happen to be safe driving practices because they encourage the driver to pay more attention to his or her surroundings, keep track of and predict traffic signal changes, keep more distance from the car in the front, and avoid sudden accelerations and decelerations of the car as well as unnecessary lane changes. So driving the car in Eco-Drive mode only made driving safer than regular driving.
The OBD II port on cars is easily accessible on the car’s dashboard and is completely safe to use.
Since student did not have the license to drive, student's mom drove the car in all the trials, while the student recorded the data during driving, such as number of traffic stops etc.
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Firstly, I would like to thank my younger brother who got me interested in cars.
I would also like to thank my mom for driving the car for me during multiple trials, for understanding the Eco-Drive practices, and for adjusting her style of driving as needed for the experiment.
Most importantly, I would like to thank my science teachers - in particular, Mrs. Nguyen from 6th Grade, Mr. Atkins from 8th grade, Mrs. Sabherwal from 9th grade, and Mr. Higgins currently in 10th Grade for sparking an interest in performing real-life experiments and for teaching me the scientific method.