A joint study from the VTT Technical Research Centre in Finland and America's Argonne National Laboratory (ANL) has concluded that at least one third of a car's fuel consumption is used in overcoming friction. Friction loss has a direct impact on both fuel consumption and as a result, air emissions. However, there is available technology and technology under development that will make it possible to reduce fuel consumption and emissions by 18 percent within a decade. Within 25 years, the researchers estimate fuel consumption can be reduced by over 60 percent.
A joint study from the VTT Technical Research Centre in Finland and America's Argonne National Laboratory (ANL) has concluded that at least one third of a car's fuel consumption is used in overcoming friction. Friction loss has a direct impact on both fuel consumption and as a result, air emissions. However, there is available technology and technology under development that will make it possible to reduce fuel consumption and emissions by 18 percent within a decade. Within 25 years, the researchers estimate fuel consumption can be reduced by over 60 percent.
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Owning and driving a car is deeply embedded into the American fabric. This nation drives more vehicles, and more miles per vehicle, than any on Earth. Around the world, car usage is also on the rise, particularly in the large modernizing Asian economies.
Automobile emissions are one of the greatest sources of greenhouse gas emissions. Plus, the acquisition of cheap oil is becoming increasingly scarcer and often comes from dangerous or unfriendly countries. This is why increasing vehicle fuel economy should be front and center in the minds of auto consumers and producers.
There are 612 million cars in the world today, and the average car drives 13,000 km per year (8,100 miles). The study found that each car has to burn 340 liters of fuel (90 gallons) just to overcome friction, costing an average 510 euros per year ($650).
For the average car engine, only 38 percent of its energy output is actually used to mechanically propel the car. The rest goes to cooling and exhaust. Of the mechanical energy actually used, 33 percent is lost to friction, plus an additional 5 percent to air resistance.
The friction loss can be further broken down as follows. 35 percent is spent overcoming rolling resistance in the wheels. Another 35 percent is lost in the engine itself. 15 percent is lost in the gearbox and another 15 percent in braking. This means in total, only 21.5 percent of the energy output of the fuel is used to move the car. The rest is wasted.
The researchers found various technologies that can drastically reduce friction loss. These include new surface coatings and textures, lubricant additives, and low friction tires inflated to higher than normal pressures. Micro-etching on the surface of a material, for instance, can be used to guide the flow of lubricants, reducing friction up to 50 percent and fuel consumption by 4 percent. Also, ionic liquids which contain electrically charged molecules can reduce friction by a further 50 percent, decreasing fuel consumption.
Other ways to influence fuel consumption is in driver behavior. Reducing top speed by 10 percent will translate into a 16% boost in fuel efficiency. Slower speeds will also make higher tire pressures possible.
There are many other innovative solutions described in the report. Each will help make driving a car more practical in the future. The report has been published in the journal, Tribology International.
Link to published article: http://www.sciencedirect.com/science/article/pii/S0301679X11003501
Image credit: hfng/Shutterstock
