1. Full load curve proposal
Requirement for special cases
2017

2. Full load curve proposal
Introduction
No in the scope:
Vehicles, with different n_min_Drive (MTs) or different gearshift behaviour;
vehicles, where the difference in power is based on technology changes, that would anyway no allow for them being in one family.
In the scope of that proposal:
There are cases, where vehicles have a reduced full load curve, that is only based an a different engine software calibration (no hardware change, no other change).
In that case, a WLTP test result would be completely identical (apart from measurement inaccuracy effects), if the gearshift points are identical.
This is the case e.g., if n_idle and n_rated is identical.
New: Idea, how to include AT vehicles is added!
Full load 1
power
Full load 2
engine speed / velocity
operating area WLTP
nidle
nmin_Drive
nrated

3. Full load curve proposal
Text proposal
Interpolation family for pure ICE vehicles
Vehicles may be part of the same interpolation family in any of the following cases including combinations of these cases:
(a) They belong to different vehicle classes as described in paragraph 2. of Annex 1;
(b) They have different levels of downscaling as described in paragraph 8. of Annex 1;
(c) They have different capped speeds as described in paragraph 9. of Annex 1.
(d) With the agreement of the responsible authority they may differ by their full-load characteristics via a different software limitation as long as that limitation does not affect:
(i) the gear shift points over the applicable WLTC, see requirements in paragraph ;
(ii) the cycle class;
(iii) the levels of downscaling;
(iv) the capped speed requirements.
Gearshift-point requirements in the case of different full-load characteristics
For manual transmission vehicles the gearshift points for vehicle H are calculated according to Annex 2 in both configurations, the higher full-load and the lower full-load characteristics, to demonstrate equivalency.
For automatic transmission vehicles the equivalency shall be demonstrated by providing the authority with the necessary information about the gearbox software and by providing a simulation for vehicle H, that is capable of adequately including all relevant effects and demonstrates equivalent gearshift-points in both configurations, the higher full-load and the lower full-load characteristics.
Only vehicles that are identical with respect to the following vehicle/power-train/transmission characteristics may be part of the same interpolation family:
(a) Type of internal combustion engine: fuel type, combustion process, engine displacement, full-load characteristics apart from cases described in paragraph (d), engine technology, and charging system, and also other engine subsystems or characteristics that have a non-negligible influence on CO2 mass emission under WLTP conditions; …
Additionally add a sentence at the end of that paragraph:
Annex 6:
General
The test vehicle shall conform…
[…]
In the case vehicles with different full-load characteristics according to paragraph (d) of this gtr are included in this Interpolation Family, the vehicle with the highest full-load characteristic is to be tested.

4. Full load curve proposal
Conclusion
In the case, that everything is identical apart from the full load curve, also the gearshift points, putting that vehicles into separate families is only administrative and testing burden, as the result would be the same.
Therefore it is justified, for the purpose of the interpolation family, to group that vehicles into one family.
Evidence has to be given to the authority (MT / AT separate procedure).
IWG: has provided feedback and improvements  Thank you!
New guidance from IWG requested:
1) As for ATs it is more complex to find a solution, it could be a way forward to start with MTs only. Would that be acceptable?
2) Feedback on approaches for MTs and ATs.
Full load 1
power
Full load 2
engine speed / velocity
operating area WLTP
nidle
nmin_Drive
nrated