This power to mass ratio (PMR) is defined as the rated power in W divided by the curb weight in kg. The test procedure is divided into 3 cycles, depending on a power to mass ratio of the tested vehicle. It is developed by European, Japanese and Indian experts in order to replace the NEDC cycle by 2013-2014. It allows to evaluate the pollutants and emissions, the fuel economy but also the electric range of light duty vehicles (passenger cars and vans). Like previous cycles, the Worldwide Harmonized Light vehicles Test Procedures (WLTP) is a test performed on chassis dynamometer. It is performed both with cold and warm start and it represents driving in congested condition, with strong accelerations and decelerations. The JC08 is a transient cycle which is much more demanding than 10-15 mode cycle. This cycle has the same disadvantages as the NEDC, that’s why Japanese authorities and manufacturers decided to switch to a more realistic cycle starting from 2011, the JC08 cycle. The measurements are performed while engine is hot, after a standard warming procedure. It simulates both urban and motorway cycle, including idling, accelerations, cruising and decelerations. The 10-15 mode Japanese cycle is being used for emissions and fuel consumption certification in Japan. Japanese driving cycles The 10-15 mode cycle This is in fact a FTP-75 performed at -7☌ ambient temperature.
The last added cycle is the “cold cycle”. This is needed for taking into account the air-conditioning in fuel consumption and emissions calculations. The SC03 is another added cycle which particularity is to be performed at 35☌ ambient temperature. Indeed, this cycle has a higher top speed of 80 mph (130 km/h) and some higher acceleration which represents a much more aggressive driving behavior. The first one is the US06, which is a complement to what is missing in FTP-75 cycle. In 2007, EPA decided to add 3 more cycles to the existing ones, in order to better reflect real world driving conditions. The Highway fuel economy test (HWFET) is used to assess fuel economy over highway driving cycle. The FTP cycle (for Federal Test Procedure) has been created by US EPA (Environmental Protection Agency) to represent a commuting cycle with a part of urban driving including frequent stops and a part of highway driving. Note that it exists several other cycles more or less used by car manufacturers like the modem-Hyzem cycle that will not be described in this featured article. However, car manufacturers use this kind of cycle to better understand real driving conditions and to assess real performances of their vehicles. Here are the main characteristics of the cycles:Īrtemis cycles are not used for certification of pollutants or fuel consumption.
It is made of 3 different configurations, plus an additional variant: the urban cycle, the rural one, the motorway 130 km/h and the motorway 150 km/h. This cycle is based on a statistical study done in Europe within the so called Artemis project.
The new cycle called Worldwide Harmonized Light Vehicle Test Procedure (WLTP) will probably appear for the upcoming norm Euro7. For those reasons, a solution to replace the NEDC is being explored by European authorities. This make impossible to obtain certified values when driving with the vehicle in real conditions. Indeed, accelerations are very soft there are a lot of constant speed cruises and a lot of idle events. This cycle is criticized by experts as it doesn’t represent real life driving conditions. Here are the main characteristics of the cycle: Distance It is made of an urban part called ECE, which is repeated four times, and an extra-urban part, the EUDC. The NEDC is used as reference cycle for homologating vehicles until Euro6 norm in Europe and some other countries.
Main difference is that modal cycles are a compilation of straight acceleration and constant speed periods and are not representative of a real driver behavior, whereas transient cycles involve many speed variations, typical of on-road driving conditions. There are two kinds of driving cycles, the modal cycles as the European standard NEDC, or Japanese 10-15 Mode and the transient cycles as the FTP-75 or Artemis cycle. In commercial vehicles area, the driving cycle is not performed on a vehicle dynamometer but on an engine dynamometer and is evaluated through a set of engine torque and speed points instead of vehicle speed points. The driving cycle is performed on a chassis dynamometer, where tailpipes emissions of the vehicle are collected and analyzed to assess the emissions rates. It is used to assess fuel consumption and pollutants emissions of a vehicle in a normalized way, so that different vehicles can be compared. A driving cycle commonly represents a set of vehicle speed points versus time.