On-the-road tests for more accurate fuel economy figures
Plans to stop the fuel economy swindle
Inaccurate advertisements are no laughing matter in the US which is why the advertised fuel economy figures of new cars stateside do not match the data reported in Europe. The Environmental Protection Agency (EPA) is still unsatisfied, though, and is considering a requirement that carmakers use on-the-road data to support their advertised mileage claims .
Objective measuring of fuel economy has many challenges. The testing procedures and their criteria vary from continent to continent, which does not make the job of the manufacturers producing cars for the global market any easier. In the EU, a strict regulation restricting the legal average carbon dioxide exhaust – directly proportional to the measured fuel consumption – of the line-up of the respective manufacturers is taking effect next year, clearly marking out the future of engine manufacturing. The reported figures are based on an admittedly outdated NEDC test, though, with little relationship to reality, unsuited for producing comparative data as it does not reflect the fuel economy experienced on the road.
Northern America is one step ahead. The fuel economy figures have been calculated by a more realistic testing procedure for quite some time over the pond, and as consumers expect to be provided with exact and reliable estimates, inaccuracies have their consequences. Recently, Ford, Hyundai, and Kia have all been fined and forced to re-state the fuel economy figures of several cars once the original ratings proved to be inaccurate. To ensure consumers won’t be duped again, the EPA now suggests car manufacturers be obliged to conduct on-the-road tests.
Fuel economy tests are currently either based on computer simulated estimates or take place on dynamometers which, according to the EPA, produce rather inaccurate results, especially for hybrids. Due to the large number of currently available models, there is no way the organization can test more than about 15% of them on dynamometers, so making the manufacturers do more realistic tests in order to provide customers with precise data is fair enough as fuel economy is a major factor in deciding what car to buy.
In Europe, replacing laboratory tests with something more realistic would be a huge step forward in itself. There’s been talk about the need for a new testing system, but switching to real life fuel consumption data would require an update of several related regulations currently based on the NEDC figures. The developments based specifically on the NEDC would become pointless, too, causing the manufacturers serious damage, so we will probably have to make do with the airy-fairy figures for years to come.