Division 6.8 Road load delta methodF1

For the purpose of including options when using the interpolation method which are not incorporated in the road load interpolation (i.e. aerodynamics, rolling resistance and mass), a delta in vehicle friction may be measured by the road load delta method (e.g. friction difference between brake systems). The following steps shall be performed:

(a)
The friction of reference vehicle R shall be measured;
(b)
The friction of the vehicle with the option (vehicle N) causing the difference in friction shall be measured;
(c)
The difference shall be calculated in accordance with paragraph 6.8.1.

These measurements shall be performed on a flat belt in accordance with paragraph 6.5. or on a chassis dynamometer in accordance with paragraph 6.6., and the correction of the results (excluding aerodynamic force) calculated in accordance with paragraph 6.7.1.

The application of this method is permitted only if the following criterion is fulfilled:

$|\frac{1}{n} \sum_{n}^{j = 1} (F_{Dj,R} - F_{Dj,N})| \leq 25 N$

where:

F_Dj,R

is the corrected resistance of vehicle R measured on the flat belt or chassis dynamometer at reference speed j calculated in accordance with paragraph 6.7.1., N;

F_Dj,N

is the corrected resistance of vehicle N measured on the flat belt or chassis dynamometer at reference speed j calculated in accordance with paragraph 6.7.1., N;

is the total number of speed points.

This alternative road load determination method may only be applied if vehicles R and N have identical aerodynamic resistance and if the measured delta appropriately covers the entire influence on the vehicle's energy consumption. This method shall not be applied if the overall accuracy of the absolute road load of vehicle N is compromised in any way.

Annotations

Textual amendments

F1: Inserted by Commission Regulation (EU) 2018/1832 of 5 November 2018 amending Directive 2007/46/EC of the European Parliament and of the Council, Commission Regulation (EC) No 692/2008 and Commission Regulation (EU) 2017/1151 for the purpose of improving the emission type approval tests and procedures for light passenger and commercial vehicles, including those for in-service conformity and real-driving emissions and introducing devices for monitoring the consumption of fuel and electric energy (Text with EEA relevance).