1. Proposal for aerodynamic options
WLTP-DTP-LabProcICE-158
Proposal for aerodynamic options
The vehicle shall be tested 3 times (3 coastdowns, 3 CO2-tests) to define the maximum bandwidth for CO2 values
TML without aerodynamic options
TMH aerodynamic without aerodyn. options and worst case
intermediate values for individual options to be calculated and added to TM CO2 value
extrapolation within a certain range should be possible
mass
CO2
TML
TMH
Aerodyn. worst case
DCO2
Aero CO2
individual values
for each option
Bandwidth of individual vehicle
TM CO2
No aerodynamic
options installed
No aerodynamic
options installed TM
Aerodynamic options add weight to the vehicle, therefore TML measurements
have to be carried out without any options
AUDI, M. Bergmann

2. Calculation of AeroCO2 Interpolated AeroCO2 values shall be based on
calculations of cdi· Ai
With „i“ for options that increase aerodynamic drop
And „n“ for the number of increasing aerodynamic options
Extrapolated AeroCO2 values shall be based on
calculations of cdd· Ad
With „d“ for options that decrease aerodynamic drop
AUDI, M. Bergmann

3. Example calculation Example for an individual vehicle:
MTMCO2 is based on a vehicle without any options MTMCO2 = 100 g/km
option of individual vehicle: sport suspension,
rocker panels, wider tyres
option
AeroCO2
[g/km]
Wheel rims (wider tyres)
0,4
Rough road suspension
1,3
Sport suspension
-0,7
Rocker panel
-0,4
Roof rails
AUDI, M. Bergmann

4. Consideration of moveable aerodynamic bodyparts
Current gtr: Proposal for moveable aerodynamic bodyparts:
„Moveable aerodynamic body parts shall operate as intended under normal driving conditions.“
Proposal with a definition of “normal driving conditions” :
Moveable aerodynamic body parts shall operate as intended for a vehicle with TMH driven through a WLTC cycle at temperatures between [283 to 313]K.
Justification
TMH to represent driving with maximum load
WLTC cycle because the cycle is representative for customers driving behaviour
The temperature range from [283 to 313] K is in accordance with the range allowed for RLD
The speed range up to 132 km/h covers the WLTC
AUDI, M. Bergmann