WLTP-06-15e
Proposal
Supplemental Test for determination of CO2 emissions under
representative regional conditions
Drafted by Audi/BMW November 2013
Definitions:
Regional soak temperature: The regional temperature is derived from statistics taking
into account the meteorological data, population and traffic density of the different areas
within Europe. On top of this a temperature offset accounting for the garage parking has
to be added. This leads to Trep= 14°C.
Soak Time: Typical use cases for soak time are overnight parking ~10-12h and daytime
parking at work ~8h. This leads to tpark= 9 h. To give flexibility for the test facilities a
tolerance of +0…2h is given.
Active heat storage: Active heat storage technology defines a technology that stores
heat within any device of a vehicle and releases the heat to a power train component
over a defined time period at engine start. It is characterized by the stored enthalpy in
the system and the time for heat release to the power train components.
Other than specified in annex 6 for the Type 1 test, the following conditions have to be met:
1.1 Ambient conditions for supplemental test
1.1.1
The vehicle shall be tested and soaked at the regional representative temperature
Trep.
1.1.2
The minimum soaking time is defined by the regional representative mean parking
time tpark.
1.2 Test cell and soak area
1.2.1 Test cell
1.2.2.1 The test cell shall have a temperature set point representative Trep. The tolerance of
the actual temperature value shall be within [± 3] K at the beginning of the test and within
[±5] K during the test.
1.2.2.2 The absolute humidity (Ha) of either the air in the test cell or the intake air of the
engine shall be such that:
5.5 ≤ Ha ≤ 12.2
(g H2O/kg dry air)
1.2.2.3. Humidity shall be measured continuously at a minimum of 1 Hz.
1.2.2.4 The air temperature and humidity shall be measured at the outlet of the vehicle
cooling fan at a rate of 1 Hz.
1.2.2. Soak area
1.2.2.1 The soak area shall have a temperature set point Trep and the tolerance of the actual
value shall be within [±3] K.
WLTP-06-15e
1.3 Test vehicle
The vehicle to be tested shall be representative for the family, for which the supplemental
data are determined (paragraph 1.9). The vehicle High configuration has to be used.
Follow prescription Annex 6, 1.2.3
1.4 Settings
1.4.1. Settings
Follow prescription Annex 4.
1.5 Preconditioning
Follow prescription Annex 6.
1.6 Soak
After this preconditioning, and before testing, vehicles shall be kept in a room with the
ambient conditions described in 1.2.2.
Soaking shall be carried out as follows:
The transfer from the preconditioning to the soak area should be done within [10] min. The
vehicle has then to be kept in the soak area at the conditions defined in 1.2.2 for at least the
defined time tpark and not longer than tpark + [2] hours without using a cooling fan, with all
body parts positioned as intended under normal parking operation.
1. 7 Emission Test
1.7.1 Emissions test: The test vehicle shall be pushed immediately onto a dynamometer and
operated through the cycles as specified in annex 1 for that class of vehicle.
1.7.2 Follow procedures of annex 6 with ambient conditions for the test cell as described in
§1.2 of this section.
1.8 Calculation and Documentation
Supplemental test data and results have to be documented following prescriptions of
Annex 7.
The CO2 correction value has to be calculated. CO2 base test is the Type I test with the
vehicle H.
The family correction factor is calculated as follows:
FCF=(CO2 Type-X@Trep) / (CO2 Type-I@296K)
The individual CO2 value for each vehicle in the family is calculated from the type I CO2
value and the FCF using the following formula:
WLTP-06-15e
CO2_ind=CO2_ind@23°C × FCF
1.9 Definition of Supplemental Test Family
A supplemental test family shall consist of vehicles which do not differ in at least the
following essential characteristics:
- Powertrain architecture (internal combustion, hybrid, electric)
- Details of combustion process (two stroke, four stroke, rotary)
- Number and arrangement of cylinders
- Method of engine combustion (e.g. indirect or direct injection)
- Type of cooling system (air, water, oil)
- Method of aspiration (naturally aspirated, charged)
- Fuel for which the engine is designed (petrol, diesel, NG, LPG, etc.)
- Capacity differences of more than [20%]
Provision for emissions control characteristics:
- 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)
Provision for cool down and heat storage characteristics:
- Similar end temperature of engine coolant for reference vehicles (H) of the combined
approach families (CAF) within the supplemental test family (STF) after driving the
respective type I test @23°C and soaking for the representative regional soak time
@23°C. The tolerance between Type 1 test end and start of cool down measurement is
[10 min]. From the measured end temperatures the average soak area temperature of
the last third of the soak process has to be substracted and the resulting temperatures
should be in a range of [5K] within the STF.
- If active heat storage systems are installed, the heat capacity and the time for heat
release 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%] for a vehicle
family. The time for heat release at engine start within a family has to be in a range [6%].