# Commission Implementing Decision (EU) 2017/1402 of 28 July 2017 on the approval of the BMW AG engine idle coasting function as an innovative technology for reducing CO2 emissions from passenger cars pursuant to Regulation (EC) No 443/2009 of the European Parliament and of the Council (Text with EEA relevance), Division 6: CALCULATION OF THE CO2 SAVINGS

Extent: E+W+S+N.I.

To calculate the CO2 savings of the innovative technology the following formula shall be used:
Formula 1:
C CO 2 = B MC − E MC − B TA − E TA × UF
Where,
C CO 2 CO2 savings [gCO2/km];
BMC Arithmetic mean of the CO2 emissions of the baseline technology vehicle under modified testing conditions [gCO2/km];
EMC Arithmetic mean of the CO2 emission of the eco-innovation technology vehicle under modified testing conditions [gCO2/km];
BTA Arithmetic mean of the CO2 emission of the baseline vehicle under type approval testing conditions [gCO2/km];
ETA Arithmetic mean of the CO2 emission of the eco-innovation technology vehicle under type approval testing conditions [gCO2/km];
UF Usage factor of the BMW engine idle coasting function is 0,62.
If it is demonstrated that the innovative technology is not active under the type approval testing conditions, the Formula 1 may be simplified as follows:
Formula 2:
C CO 2 = B MC − E MC × UF
To determine BMC, the same modified testing conditions shall be followed by a vehicle which does not have the BMW engine idle coasting function.
It shall be assumed that the baseline vehicle is able to perform a sailing curve (line 2' in Figure 2) without disconnecting the engine from the wheels, although with lower efficiency than a vehicle fitted with a BMW engine idle coasting function (i.e. able to disconnect the engine from the wheels).
Figure 2 illustrates that during the deceleration phases of the type approval (3) and the modified (2' + 3') testing conditions no fuel is used (cut-off) by the baseline vehicle.
In order to determine the CO2 emissions of the baseline vehicle under the modified conditions (BMC), those emissions shall be calculated based on the CO2 emissions of the baseline vehicle determined under type approval hot start conditions using a conversion parameter (c-factor) which takes into account the effect of the modified testing conditions in accordance with the following Formula 3:
Formula 3:
c = B MC B TA hot
As consequence, Formula 2 becomes:
Formula 4:
C CO 2 = c × B TA hot − E MC × UF
Where,
c Conversion parameter which is 0,960;
B TA hot Arithmetic mean of the CO2 emission of the baseline vehicle under type approval hot start conditions [gCO2/km];
EMC Arithmetic mean of the CO2 emission of the eco-innovation vehicle under modified testing conditions [gCO2/km];
UF Usage factor of the coasting technology for the BMW technology which is 0,62; this value is representative only for the BMW fleet.

---
Source: https://www.legislation.gov.uk/eudn/2017/1402/annex/division/6 (the official version)
Page: https://openlegislation.uk/eu-decision-2017-1402/annex/division-6
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.