Featured Research

from universities, journals, and other organizations

Car Make, Age And Fuel Economy All Affect How Much Vehicles Pollute, Study Finds

Date:
January 10, 2006
Source:
Ohio State University
Summary:
When it comes to how much automobiles pollute, some makes are cleaner than others, according to new research. A study using data on nearly 4 million cars that underwent government-mandated emissions test in three states found that cars manufactured by German auto maker BMW were the least likely to fail these state pollution tests. Cars manufactured by Hyundai, Mitsubishi, Chrysler and GM were most likely to fail.

When it comes to how much automobiles pollute, some makes are cleaner than others, according to new research.

A study using data on nearly 4 million cars that underwent government-mandated emissions test in three states found that cars manufactured by German auto maker BMW were the least likely to fail these state pollution tests. Cars manufactured by Hyundai, Mitsubishi, Chrysler and GM were most likely to fail.

While other studies have analyzed data from state emissions tests, this is the first time that researchers examined how different car makes compared, said Jean-Michel Guldmann, co-author of the study and professor of city and regional planning at Ohio State University.

“There are several factors that determine how much cars and trucks pollute, and vehicle make is one of the more significant,” Guldmann said.

In the case of trucks, Honda, Nissan and Toyota models were least likely to fail pollution tests, while Mitsubishi, Mazda and Chrysler were most likely to fail.

The study also found that the vehicles that polluted the most tended to be those that were older models, had higher mileage, poorer fuel economy, and were less-well-maintained.

And car owners worried about passing emissions tests should have their vehicles tested in spring and summer, when vehicles emitted less pollutants on average, the study showed.

“These effects were uniform, but the magnitudes were different depending on the make of the car,” Guldmann said. “Some makes are cleaner than others.”

The study was based on the doctoral dissertation of Mustapha Beydoun, who studied with Guldmann at Ohio State. Beydoun is now an assistant professor at Texas Southern University. Their results appear in the January 2006 issue of the journal Transportation Research Part D.

The researchers examined data from emissions tests in Massachusetts, Maryland and Illinois in 2001. Under the Clean Air Act, certain urban areas violating federal air quality standards are required by the U.S. Environmental Protection Agency to implement pollution emissions testing on vehicles. Currently 33 states and the District of Columbia have some type of vehicle emissions testing.

Guldmann said the samples from the three states they used are much larger and more comprehensive than those used in earlier studies, which were generally confined to one or two metropolitan areas. Earlier studies were also confined to Western states. This is also the first study to examine the role of fuel economy and vehicle maintenance in emissions.

The Massachusetts database provided the most comprehensive and consistent data on specific vehicle emissions, and was the focus of some of the analyses, Guldmann said.

Results showed that newer model cars tended to be much cleaner than older ones. For example, a 1985 vehicle averages almost 38 times more carbon monoxide emissions per mile than a 2001 model. But again, the make of the car has a large influence. Toyota vehicles tended to have the least difference between older and newer cars, because their older cars tended to be already lower polluting, Guldmann said.

But other foreign models – Honda, Nissan and Hyundai – had a much greater age effect, with their older models showing relatively high levels of pollution emissions.

“The effects of age and other factors on pollution levels are stronger for some vehicle makes than others,” Guldmann said. “It's not always foreign cars that are better. It really depends on what pollutant or variable you are measuring.”

The fact that cars polluted less in spring and summer is probably linked to both differences in atmospheric conditions, and changes in fuel mixtures produced by refineries during different seasons, Guldmann said.

The finding that cars with better gas mileage also polluted less is important, Guldmann said. It suggests that current regulations, which measure emissions in grams per mile driven, should be changed to grams per gallon of gasoline used.

“This would ensure that higher fuel economy standards are automatically translated into emissions reductions,” he said.

Other factors studied by the researchers, such as vehicle weight, number of cylinders, and engine displacement, had mixed results with no clear effect on emissions of pollutants, according to Guldmann.


Story Source:

The above story is based on materials provided by Ohio State University. Note: Materials may be edited for content and length.


Cite This Page:

Ohio State University. "Car Make, Age And Fuel Economy All Affect How Much Vehicles Pollute, Study Finds." ScienceDaily. ScienceDaily, 10 January 2006. <www.sciencedaily.com/releases/2006/01/060110094710.htm>.
Ohio State University. (2006, January 10). Car Make, Age And Fuel Economy All Affect How Much Vehicles Pollute, Study Finds. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2006/01/060110094710.htm
Ohio State University. "Car Make, Age And Fuel Economy All Affect How Much Vehicles Pollute, Study Finds." ScienceDaily. www.sciencedaily.com/releases/2006/01/060110094710.htm (accessed July 25, 2014).

Share This




More Matter & Energy News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com
Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins