Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Car make, age and fuel economy all affect how much vehicles pollute

10.01.2006


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.

Jean-Michel Guldmann | EurekAlert!
Further information:
http://www.osu.edu

More articles from Studies and Analyses:

nachricht Antarctic Ice Sheet mass loss has increased
14.06.2018 | Technische Universität Dresden

nachricht WAKE-UP provides new treatment option for stroke patients | International study led by UKE
17.05.2018 | Universitätsklinikum Hamburg-Eppendorf

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>