by vox_mundi » Thu 26 Mar 2015, 12:43:14
Gasoline use at lowest rate in three decades$this->bbcode_second_pass_quote('', 'A')verage fuel consumption by American drivers is at its lowest level in at least 30 years, says a University of Michigan researcher.
In a follow-up to a series of reports released over the past two years, Michael Sivak of the U-M Transportation Research Institute examined recent trends in fuel consumption by cars, pickup trucks, SUVs and vans in the U.S. fleet from 1984 to 2013.
His findings show that gallons of gasoline consumed per person, driver, vehicle and household are below 1984 levels—the first year of the study—and down 14 percent to 19 percent from peak levels a little more than a decade ago (2003-2004).
"Despite population growth of 8 percent, the absolute amount of fuel consumed by light-duty vehicles decreased by 11 percent during the period 2004—the year of maximum consumption—through 2013," said Sivak, a research professor at UMTRI and director of the Sustainable Worldwide Transportation research consortium.
Sivak found that in 2013 the amount of fuel consumed was about 392 gallons per person (down 17 percent from 2004), 583 gallons per driver (down 16 percent from 2004), 524 gallons per vehicle (down 14 percent from 2003) and 1,011 gallons per household (down 19 percent from 2004).
In 1984, annual fuel-consumption rates were 400 gallons per person, 608 gallons per driver, 602 gallons per vehicle and 1,106 gallons per household.
In addition to examining changes in fuel consumption, the study also analyzed changes in the number of vehicles and distance driven. For both measures, rates per person, driver, vehicle and household are at their lowest levels since the 1990s.
Running on empty: Gas guzzlers on the decline$this->bbcode_second_pass_quote('', 'I')n 2008, half of new-car buyers in the U.S. bought vehicles that were rated at less than 20 mpg. Today, just over a quarter do so.
Building on research that shows average fuel economy has improved 4.5 mpg between model years 2008 and 2014, University of Michigan researchers Michael Sivak and Brandon Schoettle document sales-weighted distributions for the same model year vehicles (cars, pickup trucks, vans and SUVs).
Their new report found that improvements are present throughout the distributions of vehicle fuel economy.
About 24 percent of consumers bought new 2008 vehicles with fuel economy between 11 mpg and 17 mpg, and 26 percent purchased vehicles with mpg between 17 and 20. Six years later, less than 9 percent of car buyers bought a new 2014 model with fuel economy less than 17 mpg. Another 19 percent drove new cars that averaged between 17 mpg and 20 mpg.
While about 35 percent of new vehicles sold in 2008 had average fuel economy between 20 mpg and 26 mpg, compared to roughly 31 percent for model year 2014, huge improvements were made in the sales of fuel-efficient cars, the researchers say.
Nearly 41 percent of new-car buyers bought 2014 vehicles with mpg of at least 26, including 27 percent who purchased vehicles averaging at least 30 mpg. In 2008, the corresponding figures were 15 percent and 5 percent, respectively.
Overall, average fuel economy for light-duty vehicles improved from 20.8 mpg for model year 2008 to 25.3 mpg for model year 2014.
"Overall, the combined evidence from this and the previous studies indicates that—per person, per driver and per household—we now have fewer light-duty vehicles, we drive each of them less and we consume less fuel than in the past. There is no evidence in the 2013 data that the peaks in the rates that we experienced about 10 years ago were temporary."Read more at:
http://phys.org/news/2015-03-gasoline-l ... s.html#jCp
$this->bbcode_second_pass_quote('', 'T')his report analyzes recent trends in the amount of energy needed to transport a person in the U.S. a given distance either in a light-duty vehicle or on a scheduled airline flight. After observing that the energy intensity of driving (BTU per person mile) is 57% greater than that of flying, calculations were made to estimate how much improvement would need to be achieved in either vehicle fuel economy or passenger load to make driving the less energy intensive of these two modes of transportation.
The report briefly discusses the difficulties in achieving these improvements. Furthermore, it points out that, because the future energy intensity of flying will be better than it currently is, the calculated improvements underestimate the improvements that need to be achieved for driving to be less energy intensive than flying. Finally, it is emphasized that, although flying is less energy intensive than driving, flying is a viable alternative to driving only for a subset of driving trips that involve relatively long distances.