40% Gap Between Official & Real-World Fuel Economy Figures In Europe

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The divide between official fuel-economy figures put out in Europe by auto companies (and others) and the actual real-world realities has now hit 40%, according to the latest figures provided by the International Council on Clean Transportation (ICCT).

Given the ongoing Volkswagen diesel car scandal, and other news concerning related frauds, these recent figures seem to simply be showing the European Union’s regulatory bodies in an even worse light. Just how much is fraud and corruption a common part of the EU’s body?


Interestingly, this discrepancy between reality and “official reality” has been growing significantly over the last 15 years — with the discrepancy actually (somehow) more than quadrupling during this period. This discrepancy relates to roughly €450 ($500) a year in added fuel costs for most drivers. That really doesn’t put the leadership of the EU in a good light in my eyes — especially considering that the German government (the de facto leader of the EU) appears to be complicit in the fraud to some degree or another.

The new report, it should be noted, was jointly prepared by a German group (the Institut für Energie- und Umweltforschung Heidelberg), the Netherlands’ Organisation for Applied Scientific Research (TNO), and ICCT.

Here’s an excerpt: “A technical definition of real-world driving is elusive because of variations in vehicle types, driving behavior, and driving conditions. Nonetheless, in aggregating data on almost 600,000 vehicles from eleven data sources and six countries, this study reveals a clear trend over time: the divergence (or “gap”) between real-world and official CO2 emissions increased from approximately 8% in 2001 to 40% in 2014. Each data source used for the study includes a unique set of vehicles and drivers, so estimates of the divergence of real-world from official values vary among them. however, the increase in the gap cannot be explained based on driving behavior or differences between the data sources, but is instead a result of increasingly unrealistic type-approval values.”


Green Car Congress provides more:

The researchers assessed in detail the underlying reasons for the growing divergence, and identified four key factors:

Chassis dynamometer testing. Under the EU regulation, there are a number of “loopholes” that can potentially be exploited by vehicle manufacturers during chassis dynamometer testing. These include break-in periods for the test vehicle, tolerances regarding laboratory instruments, the state of charge of the vehicle’s battery, special test driving techniques, and use of pre-series parts that are not representative of production vehicles. The ICCT analysis indicates that vehicle manufacturers have found ways to optimize chassis dynamometer type-approval testing over time, which at the same time made it less representative of average real-world driving conditions. As a result, the impact of chassis dynamometer testing flexibilities on the divergence between type-approval and real-world CO2 emissions today is estimated to explain more than half of the overall divergence observed.

Road load determination. Coefficients for road load are used to characterize the forces (mainly aerodynamic drag and rolling resistance) that a car needs to overcome as it is driven on the road. These coefficients are determined through a series of coast-down tests on an outside track. There are a number of aspects of this road load determination procedure that offer vehicle manufacturers potential for exploiting tolerances and flexibilities, ICCT said. These include tire selection and preparation, selection of the test track, ambient test conditions, and pre-conditioning of the vehicle, among others. The ICCT team estimated that about one-quarter of the overall gap observed in 2014 is explained by exploitation of tolerances and flexibilities in the methods required by the EU regulation for determining road load.

Technology deployment. Certain technologies, such as stop-start systems and hybrid powertrains, have a different effect on CO2 emissions in the type-approval procedure than they do during real-world driving, because of specific characteristics of the driving cycle used in type-approval testing that differ from typical everyday vehicle operation. ICCT estimated that about one-tenth of the gap in 2014 is explained by an increasing market share of those technologies.

Other parameters. Running air conditioning systems and entertainment systems increases fuel consumption during real-world driving. Nonetheless, these devices are either switched off or are not fully taken into account during the type-approval emissions test, leading to unrealistically low CO2emission values. ICCT put the contribution of these factors at about another one-tenth of the gap in 2014.

The report summed these issues up thusly: “For car manufacturers, the divergence puts those that want to report realistic CO2 emission values at a competitive disadvantage. unrealistic type-approval values also have the potential to damage manufacturers’ credibility and may erode consumer and regulator trust in the entire industry.”

A final note here: new “real world” testing is expected to enter widespread use in the EU in the coming years (beginning as early as 2017). Of course, these testing protocols will no doubt have their own loopholes as well. Perhaps what’s truly needed here is the implementation of harsher penalties for offenders?

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James Ayre

James Ayre's background is predominantly in geopolitics and history, but he has an obsessive interest in pretty much everything. After an early life spent in the Imperial Free City of Dortmund, James followed the river Ruhr to Cofbuokheim, where he attended the University of Astnide. And where he also briefly considered entering the coal mining business. He currently writes for a living, on a broad variety of subjects, ranging from science, to politics, to military history, to renewable energy.

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