Fuel consumption and emissions can be reduced with new technology
No less than one third of a car´s fuel consumption is spent in overcoming
friction, and this friction loss has a direct impact on both fuel consumption
and emissions. However, new technology can reduce friction by anything from
10% to 80% in various components of a car, according to a joint study by VTT
Technical Research Centre of Finland and Argonne National Laboratory (ANL) in
USA. It should thus be possible to reduce car´s fuel consumption and emissions
by 18% within the next 5 to 10 years and up to 61% within 15 to 25 years.
There are 612 million cars in the world today. The average car clocks up about
13,000 km per year, and in the meantime burns 340 litres of fuel just to
overcome friction, costing the driver EUR 510 per year.
the energy output of fuel in a car engine, 33% is spent in exhaust, 29% in
cooling and 38% in mechanical energy, of which friction losses account for 33%
and air resistance for 5%. By comparison, an electric car has only half the
friction loss of that of a car with a conventional internal combustion engine.
friction loss in an average car worldwide amounts to 11,860 MJ: of this, 35%
is spent in overcoming rolling resistance in the wheels, 35% in the engine
itself, 15% in the gearbox and 15% in braking. With current technology, only
21.5% of the energy output of the fuel is used to actually move the car; the
rest is wasted.
Worldwide savings with new technology
recent VTT and ANL study shows that friction in cars can be reduced with new
technologies such as new surface coatings, surface textures, lubricant
additives, low-viscosity lubricants, ionic liquids and low-friction tyres
inflated to pressures higher than normal.
Friction can be
reduced by 10% to 50% using new surface technologies such as diamond-like
carbon materials and nanocomposites. Laser texturing can be employed to etch a
microtopography on the surface of the material to guide the lubricant flow and
internal pressures so as to reduce friction by 25% to 50% and fuel consumption
by 4%. Ionic liquids are made up of electrically charged molecules that repel
one another, enabling a further 25% to 50% reduction in friction.
2009, a total of 208,000 million litres of fuel was burned in cars worldwide
just to overcome friction; this amounts to 7.3 million TJ (terajoules) of
energy. Theoretically, introducing the best current technological solutions in
all of the world’s cars could save EUR 348,000 million per year; the best
scientifically proven solutions known today could save EUR 576,000 million per
year, and the best solutions to emerge over the next 10 years could save EUR
659,000 million per year.
Realistically, though, over a
period of 5 to 10 years of enhanced action and product development measures
could be expected to enable savings of 117,000 million litres in fuel
consumption per year, representing an 18% reduction from the present level.
Furthermore, in realistic terms, carbon dioxide emissions could be expected to
decrease by 290 million tonnes per year and financial savings to amount to EUR
174,000 million per year in the short term.
influence fuel consumption
A driver can significantly
influence the fuel consumption of his or her car. A reduction of 10% in
driving speed, e.g. from 110 km/h to 100 km/h, translates into a 16% saving in
fuel consumption. Slower speeds also allow for higher tyre pressures; an
increase from 2 bar to 2.5 bar can translate into a 3% saving in fuel
VTT and ANL calculated friction loss in cars
worldwide using a method that incorporated total crude oil consumption and
fuel consumption of cars, the energy consumption of an average car, and the
energy that an average car uses to overcome friction.
losses were accounted for in the subsystems of a car – tyres, engine, gearbox,
brakes – and also in its components, such as gears, bearings, gaskets and
pistons. The friction losses caused at friction points and lubrication points
were also considered.
The study was conducted at the Metal
Products and Mechanical Engineering strategic competence cluster in the DEMAPP
programme, co-ordinated by FIMECC Oy, where practical solutions for minimising
friction loss are also being developed. The study was funded by the Finnish
Funding Agency for Technology and Innovation (Tekes), VTT and FIMECC Oy, and
the Argonne National Laboratory, Department of Energy (Chicago, USA).
recent research report on friction loss in cars and the potential for reducing
energy consumption and carbon dioxide emissions was published in the Tribology
International scientific journal. The article can be accessed here: http://dx.doi.org/10.1016/j.triboint.2011.11.022