The manufacturer BMW AG (the ‘Applicant’) submitted an application for the approval of an engine idle coasting function as an eco-innovation on 23 June 2016. The completeness of the application was assessed in accordance with Article 4 of Implementing Regulation (EU) No 725/2011. The application was found to be complete.

The application refers to the BMW AG ‘engine idle coasting’ function to be used in BMW M1 vehicles with conventional powertrain and automatic transmission. The basic principle of this innovative technology is to decouple the combustion engine from the drivetrain and prevent deceleration caused by engine braking. The function should be automatically activated in the predominant driving mode, which is the mode automatically selected when the vehicle is switched on. Thus coasting can be used to increase the rolling distance of the vehicle in situations where no propulsion or a slow reduction of speed is needed. When ‘coasting’, the kinetic and potential energy of the vehicle is directly used to overcome driving resistance and, as consequence, to decrease fuel consumption. To obtain less deceleration the engine is decoupled from the drivetrain by opening a clutch. This is done automatically by the control unit of the automatic transmission. During these coasting phases the engine is running at idle speed (‘engine idle coasting’).

The applicant has provided a methodology for testing the CO₂ reductions from the use of the engine idle coasting function, including a modified NEDC test cycle to offer the possibility for the vehicle to coast. To compare the vehicle fitted with engine idle coasting function with a baseline vehicle where the coasting function is not installed, not available in the predominant driving mode or disabled for testing purposes, both vehicles should be tested on the same modified NEDC test cycle. However, in view of the difficulties for the baseline vehicle to follow the speed-trace of the modified NEDC test cycle, the test of the baseline vehicle is performed on the standard NEDC under hot start conditions, while the modified conditions are taken into account by a conversion factor being applied for the calculation of the CO₂ savings. The determination of the conversion factor is vehicle-specific and related primarily to the powertrain hardware configuration. Based on previous studies, the conversion factor appears to lie within the range 0,96 to 0,99. The applicant has requested that the conversion factor should be set at the level of 0,98. The Commission finds however that the applicant has not provided sufficient evidence for justifying a conversion factor higher than 0,96. In view of this, it is considered appropriate to maintain the conversion factor at the lower end of the identified range, i.e. at the value of 0,960, in line with the conversion factor defined in Implementing Decision (EU) 2015/1132.

A key element in determining the CO₂ savings is the proportion of the distance travelled by the vehicle over which the coasting function will be activated, taking into account that the coasting function may be deactivated in other driving modes than the predominant driving mode. The applicant has proposed a usage factor of 0,7 which relates the observed distance covered under coasting conditions during real world driving tests to the coasting distance under modified NEDC conditions. However, that proposed usage factor resulted as a best case value without robust supporting analysis. Based on additional analysis and taking into account the analysis made for the purpose of Implementing Decision (EU) 2015/1132, it is appropriate to consider a more conservative usage factor equal to 0,62.

The case study conducted by BMW AG concerned two vehicles having the engine idle coasting technology active until 40km/h. In view of the forthcoming production of BMW models able to coast until 15km/h, the applicant has proposed an analytical method to extend the scope to also cover this longer coasting activation period. Nevertheless, the influence of the more extended coasting period upon the usage factor has not been analysed by the applicant. Therefore, it is appropriate to consider the coasting function as active at least down to 40 km/h.

The information provided in the application demonstrates that the conditions defined in Articles 2 and 4 of Implementing Regulation (EU) No 725/2011 and the criteria referred to in Article 12 of Regulation (EC) No 443/2009 have been met for at least one of the two vehicles presented in the case study. Moreover, the application is supported by a verification report established by an independent and certified body in accordance with Article 7 of Implementing Regulation (EU) No 725/2011.

Based on the information provided with the current application, and taking into account the experience gained from the assessment of the application on the approval of the Porsche AG coasting function in the framework of Implementing Decision (EU) 2015/1132, it has been satisfactorily demonstrated that the BMW engine idle coasting function can provide a reduction in CO₂ emissions of at least 1 g CO₂/km in accordance with Article 9 of Implementing Regulation (EU) No 725/2011 for certain BMW vehicles. It is therefore necessary for the type approval authority, to verify that the 1gCO₂/km threshold specified in Article 9 of Implementing Regulation (EU) No 725/2011 is met for the certification of the CO₂ savings from BMW vehicles fitted with engine idle coasting function.

Against that background, the Commission finds that no objections should be raised as regards the approval of the innovative technology in question.

The manufacturer BMW AG should, in order to have the CO₂ savings from the BMW AG engine idle coasting function certified, provide a verification report from an independent and certified body confirming the compliance of the fitted vehicle with the conditions specified in this Decision together with the application for certification to the type approval authority.