1. GTR 15 clarification on 3g family extension rule renault

2. FAMILY extension interpretations
Clarification
FAMILY extension interpretations
Paragraph of Annex 6 allow the extrapolation of the interpolation line:
At the request of the manufacturer and with approval of the responsible authority, the interpolation line may be extrapolated to a maximum of 3 g/km above the CO2 emission of vehicle H and/or below the CO2 emission of vehicle L. This extension is valid only within the boundaries of the interpolation range specified in this paragraph. […]
Two possible interpretations of “CO2 emission of vehicle H”:
CO2 test result of vehicle H CO2 value of vehicle H resulting from step 9 of Table A7/1 of Annex 7 (MCO2,c,H)
CO2 calculation result of individual vehicle H CO2 value of vehicle H resulting from step 10 of Table A7/1 of Annex 7 (MCO2,c,ind,H)
The same apply to vehicle L

3. FAMILY extension interpretations
Clarification
FAMILY extension interpretations
If the interpretation is: 'CO2 test result of vehicle H’
In certain cases, margin to introduce a new vehicle on the family are reduced.
For the same vehicle the 3 g/km range is dependent to the tyre RRC used to define the road load.
Example
vehicle H using tyre w/ lower rolling resistance of his energy class (RRC = 10.6)
3 g/km
Energy efficiency class
Range of RRC for C1 tyres
Value of RRC to be used for interpolation for C1 tyres 5
10.5 < RRC ≤ 12.0
RCC = 11.3
MCO2,c,H
(RRC = 10.6)
MCO2,c,ind,new
MCO2,c,ind,H
(RCC = 11.3)

4. FAMILY extension interpretations
Clarification
FAMILY extension interpretations
If the interpretation is: 'CO2 calculation result of vehicle H’
Margin to introduce a new vehicle on the family is coherent with the vehicle H.
For the same vehicle the 3 g/km range is independent to the tyre RRC used to define the road load.
Example
vehicle H using tyre w/ lower rolling resistance of his energy class (RRC = 10.6)
3 g/km
Energy efficiency class
Range of RRC for C1 tyres
Value of RRC to be used for interpolation for C1 tyres 5
10.5 < RRC ≤ 12.0
RCC = 11.3
MCO2,c,H
(RRC = 10.6)
MCO2,c,ind,new
MCO2,c,ind,H
(RCC = 11.3)

6. Back up slides

7. For each of the test vehicles H and L:
Source
Input
Process
Output
Step No.
Step 8
For each of the test vehicles H and L:
Mi,c,8, g/km;
MCO2,c,8, g/km;
MCO2,p,8, g/km;
FCc,8, l/100 km;
FCp,8, l/100 km.
If a test vehicle L was tested in addition to a test vehicle H, the resulting criteria emission values of L and H shall be the arithmetic average and are referred to as Mi,c.
At request of a contracting party, the averaging of the criteria emissions may be omitted and the values of H and L remain separated.
Otherwise, if no vehicle L was tested, Mi,c = Mi,c,8
For CO2 and FC, the values derived in step 8 shall be used, and CO2 values shall be rounded according to paragraph 7. of this UN GTR to two decimal places, and FC values shall be rounded according to paragraph 7. of this UN GTR to three decimal places.
Mi,c, g/km;
MCO2,c,H, g/km;
MCO2,p,H, g/km;
FCc,H, l/100 km;
FCp,H, l/100 km;
and if a vehicle L was tested:
MCO2,c,L, g/km;
MCO2,p,L, g/km;
FCc,L, l/100 km;
FCp,L, l/100 km. 9
Interpolati on family result.
Final criteria emission result.
Source
Input
Process
Output
Step No.
Step 9
MCO2,c,H, g/km;
MCO2,p,H, g/km;
FCc,H, l/100 km;
FCp,H, l/100 km;
and if a vehicle L was tested:
MCO2,c,L, g/km;
MCO2,p,L, g/km;
FCc,L, l/100 km;
FCp,L, l/100 km.
Fuel consumption and CO2 calculations for individual vehicles in an interpolation family.
Paragraph of this annex.
CO2 emissions shall be expressed in grams per kilometre (g/km) rounded to the nearest whole number;
FC values shall be rounded according to paragraph 7. of this UN GTR to one decimal place, expressed in (l/100 km).
MCO2,c,ind g/km;
MCO2,p,ind, g/km;
FCc,ind l/100 km;
FCp,ind, l/100 km. 10
Result of an individual vehicle.
Final CO2 and FC result.