1. Temperature correction supplemental test: Update
C. Griard, L. Bigi

2. Motivation
The main objective is to validate the family definition by showing that the tolerances within the current family definition do not lead to significant CO2 differences for regional temperature correction and fix the temperature range for family definition
To do such a demonstration, it has been asked to perform chassis roller tests by following the below procedure with an update from BMW concerning the time tolerance between the end of the test and the beginning of temperatures recordings:

3. Test configuration (reminder)
It has been chosen to evaluate two vehicles included in the same family (regarding current definition; see slide ) that are at the corners of some family criterias (volume displacement and gearbox) to emphasise CO2 differences.
The two vehicles chosen were:
A C5 2 liters Diesel AT (6 gears)
A 208 1,4 liters AMT
The engine volume displacement differs from 30% that is the maximum allowed in a family
Both are 4 stroke Diesel turbocharged engines with same type of cooling and EGR system

4. CO2 results update CO2 results: Vehicle Test number Temperature
FCF CO2 (%)
C5 2 liters Diesel AT 2
14°C and 23°C
Tests series 1/Family Correction Factor (FCF) --
2,75 %
Tests series 2/Family Correction Factor (FCF)
1,37 %
Average Family Correction Factor (FCF)
2,06%
208 1,4 liters Diesel AMT
Tests series 1/Family Family Correction Factor (FCF)
2,12 %
Tests series 2/Family Family Correction Factor (FCF)
2,03 %
2,08%

5. CO2 results update: comments
The CO2 difference between 14°C and 23°C:
is around 2%
is close to BMW results
is close between the two vehicles that are at the opposite corners for the current family definition
One should pay attention to CO2 measurement accuracy on chassis roller
order of magnitude evaluated in the context of french round robin tests = 1,5% to 2% (current test procedure).
As an example, the average 2,06% figure on the C5 hides a dispersion due to CO2 measurement accuracy
Proposal
no CO2 correction below the CO2 measurement accuracy
X% to be determined and confirmed during the RRT

6. Cool down temperature results
Average soak engine coolant temperatures on the last third part:
The average temperature differences are below 5°C
Based on these results, a proposal of a 5K absolute temperature tolerance seems reasonable but need more confirmation.
Vehicle
14°C, 9h
23°C, 9h
Test 1
Test 2 C5
T_amb+1,5°C
T_amb+4,5°C
T_amb+3°C
208
T_amb+1°C
DT=3°C
DT=3°C

7. Next steps Same tests will be operated on a gasoline applications
Availability by end of March 2014

8. Annex: Temperature correction Family Definition

9. Temperature correction family definition
A family is defined by:
Part1: - combustion process (two stroke, four stroke, rotary)
- number of cylinders
- configuration of the cylinder block (in-line, V, radial, horizontally opposed,…) The inclination or orientation of the cylinders is not a criteria)
- method of engine fuelling (e.g. indirect or direct injection)
- type of cooling system (air, water, oil)
- method of aspiration (naturally aspirated, pressure charged)
- fuel for which the engine is designed (petrol, diesel, NG, LPG, etc.)
- engine cylinder capacity of the largest engine within the family minus 30 %
Provision to meet EU demand on EU5&6 family:
- type of catalytic converter (three-way catalyst, lean NOx trap, SCR, lean NOx catalyst or other(s)
- type of particulate trap (with or without)
- exhaust gas recirculation (with or without, cooled or non cooled)
Part2: - similar temperatures of engine oil and coolant of TMH reference vehicles of the combined approach families (CAF) within the temperature correction family (TCF) after driving the respective type I and soaking for the representative regional soak From the measured temperatures the average soak area temperature of the last third of the soak process has to be subtracted and the resulting temperatures should be within a range of [10]K (mean Value ±[5]K) within the TCF.
- If active heat storage systems are installed, the heat capacity within the family has to be comparable as follows: the heat capacity is defined by the enthalpy stored in the system and has to be within a range of [6] % (mean value ± 3%) for a vehicle family.