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Vehicle emissions testing in the EU: Why we are still struggling with the dead hand of the past—and what the future is likely to bring

The Committee on Climate Change (CCC) was established in 2008 to advise the British government on emissions targets and report to Parliament on progress made in reducing greenhouse gas emissions and...Manufacturers effectively exploit loopholes in the vehicle CO2 emissions test procedure. The WLTP will help, but can't solve the problem entirely; we need in-use conformity and on-road testing in the...
Published 2015.09.09: Blog Post

Heavy-duty vehicle fuel-efficiency simulation: A comparison of US and EU tools

Vehicle simulation tools can enable a reliable estimation of the fuel efficiency of heavy-duty vehicles while eliminating undesirable sources of variation, such as driver behavior or the influence of...
Published 2015.05.11: Publication

Improving the conversions between the various passenger vehicle fuel economy/CO2 emission standards around the world

Most governments of countries (or, in the case of the European Union, regions) with large auto markets regulate passenger vehicle fuel efficiency or CO2 emissions (essentially the same thing, since...We've updated our comparison of passenger vehicle fuel-efficiency standards worldwide, improving the test cycle conversion factors used to translate the standard values among the different...
Published 2014.12.03: Blog Post

Development of test cycle conversion factors among worldwide light-duty vehicle CO2 emission standards

Comparing the light-duty vehicle fuel efficiency standards in effect in the world's largest auto markets is not a simple, straightforward process, because any fair, apples-to-apples comparison must...
Published 2014.12.03: Publication

Measuring in-use fuel economy: Summary of pilot studies

Vehicle fuel economy is determined via a type-approval or certification process, which involves testing vehicles under laboratory conditions. But the information obtained via chassis testing under...
Published 2013.12.06: Publication

Of hybrids, metrics, and C-Maxes

The recent spate of news on Ford lowering the mileage rating on its C-Max hybrid (e.g., here and here and here) could lead some to question the in-use fuel economy benefits of hybrids. That would be...The recent spate of news on Ford lowering the mileage rating on its C-Max hybrid could lead some to question the in-use fuel economy benefits of hybrids. That would be a mistake.
Published 2013.08.16: Blog Post

In-use Testing for CO2 and Fuel Economy in the United States

  China is considering including an after-production conformity test as part of China’s Phase 3 passenger car fuel consumption standard implementation and enforcement plan and is looking for...
Published 2012.03.09: Publication

Inertia classes, vehicle emissions tests, and the dead hand of the past

Test procedures are a key feature of any system of regulating vehicle emissions. Vehicle emissions testing* involves running a vehicle on a chassis dynamometer, which (among other things) simulates...The current system of using inertia classes for vehicle emissions testing is an anachronism, kept in place by force of habit rather than force of logic. And it has the bad effect of allowing...
Published 2011.12.09: Blog Post

Focus on inertia classes

For historic reasons we make use of inertia classes and upper limits for inertia mass during the vehicle testing procedures today. Historically, the weight of a vehicle was represented by hanging...
Published 2011.10.19: Publication

Inertia classes proposal

Historically the weight of a vehicle was represented by hanging rotating inertia mass on a dynamometer. This approach required the use of discrete inertia classes and an upper limit for inertia mass...
Published 2011.06.17: Publication

Inertia classes in worldwide harmonized light vehicle test procedure (WLTP) development

The definition of vehicle weight used for testing procedures is an important decision when drafting the regulation on determining emission values under the WLTP. Currently, different inertia class...
Published 2011.05.18: Publication

Modeling heavy-duty vehicle fuel economy based on cycle properties

  This study, by researchers at the West Virginia University Center for Alternative Fuels, Engines and Emissions, developed a methodology for predicting heavy‐duty vehicle fuel economy during...
Published 2009.09.24: Publication

Evaluation of vehicle simulation tools

Among the numerous technical and regulatory design issues related to developing fuel economy or greenhouse gas standards for heavy-duty vehicles is the problem of determining the test method(s) to be...
Published 2009.08.09: Publication