Outline • Gasoline and diesel PCs: new subsector classification • Gasoline and diesel PCs:CO2 correction option • Diesel PCs Euro 5/6: Emissions update • PCs: E85 subsector (new) • Mopeds: Emissions update • Gasoline PCs: Methane update • PCs: CNG subsector (new)
New PC subsectors (gasoline and diesel) • The Gasoline<0.8 l subsector has been added for gasoline passenger cars of Euro 4-6 technologies • Gasoline<1.4 l subsector becomes Gasoline 0.8-1.4 l • The Diesel<1.4 l subsector has been added for diesel passenger cars of Euro 4-6 technologies • Diesel <2.0l subsector becomes Diesel 1.4-2.0 l
Modelling Approach for new subsectors • GOAL: to provide FC factors using simulated vehicles models (no difference in emission factors) • Use of specific vehicle features (where available) to design powertrain system level simulations (AVL CRUISE) • Collection/estimation of vehicle technical specifications: • physical characteristics (weight, wheel base, drag coefficient, tyre dimensions, etc.) • vehicle architecture and control systems
Modelling Approach • Model building • embedding of performance (energy, emission, output, …) maps for main components (engine, motor, battery, transmission) based on available data or expected improvements • Calibration of vehicle model performance via cycle testing • Type approval cycle runs (NEDC, EUDC, UDC) and acceleration data based on available data for validation purposes only. • ARTEMIS cycles for real-world fuel consumption estimation
Gasoline <0.8l modelling • Starting with the CO2 monitoring database, three representative passenger cars with an engine capacity of less than 800cc were chosen (based on their popularity and engine capacity distribution) • This subsector contained a very limited choice of passenger cars. • Simulation was weighted based on vehicle registrations.
Gasoline <0.8l models • The Fiat 500 vehicle typically exceeds the 0.8l range. However, due to the limited of vehicles in the CO2 database and the low-consumption performance of this vehicle, it was still included in the simulation.
Gasoline <0.8l results • The fitting equation type was based on the Gasoline <1.4l, since this subsector is a subset. • Goodness of fit: • Adjusted R-square: 0.884 • RMSE: 3.558
Diesel <1.4l modelling • Using the CO2 monitoring database six representative passenger cars with an engine capacity of less than 1400cc were chosen (based on their popularity and engine capacity distribution) • Simulation was weighted based on vehicle registrations.
Diesel <1.4 l results • The fitting equation type was based on the Diesel<2l since this subsector is a subset. • Goodness of fit: • Adjusted R-square: 0.6971 • RMSE: 2.456
Diesel <1.4 l validation • Average vehicle results as well as the FC emission factor were compared to the A300DB content on Diesel<1,4 l Euro 4 & 5 cars. • The difference is similar to differences between this database and higher capacity diesel vehicles in COPERT.
CO2 Correction: Real-world vs. Type Approval • Type-approval emissions are not considered representative of real-world driving conditions • According to the JRC Report: • “Parameterisation of fuel consumption and CO2 emissions of passenger cars and light commercial vehicles for modelling purposes,” • a set of models based on type-approval FC, and vehicle mass can predict real-world fuel consumption
CO2 Correction: Modelling logic • A simple model should be introduced into COPERT methodology • The chosen set of models • can be used for all passenger car capacities • is ideal to predict consumption of new car registrations because it uses mean vehicle mass, capacity, and type-approval CO2 to correct emissions, which are readily available from the CO2 monitoring database
CO2 Correction: Modelling details • The model equations for the real-world fuel consumption of passenger cars are: • Where FCTA stands for type-approval fuel consumption, mstands for the vehicle reference mass (empty weight + 75 kg for driver and 20 kg for fuel), and CC stands for the engine capacity in cm3):
CO2 Correction option • Average values for mass, engine capacity, and TA CO2 figures are required user input, per passenger car category • COPERT first calculates emissions normally, based on custom input circulation data • If the CO2 correction option is selected, a calibration process introduces a correction coefficient • This coefficient is then used to calculate the modified FC and CO2 emission factors
Example: Gasoline<1.4, Euro 5 • COPERT calculated FC emission factors (U/R/H): 50.0/ 44.3/ 48.2 g/km • Speed profile: 40/ 60/ 100 km/h • Shares: U20%/ R40%/ H40% • The model fuel consumption for Euro 5 cars <1.4 l leads to 6.41 l/100km or 48.1 g/km. This reflects mean consumption over CADC. • average mass: 1200 kg • average capacity: 1150cc • average type-approval FC: 40 g/km (~5.26 l/100km)
CO2 Correction example: Gasoline<1.4l • The average consumption of vehicles over CADC on which the COPERT 4 emission factors is based is 59.5 g/km • Hence a correction coefficient has to be introduced of 48.1/ 59.5 = 0.808 • Applying the coefficient will produce modified FCs of • 0.808 x 50.0 = 40.4 g/km for urban (was 50 g/km) • 0.808 x 44.3 = 35.8 g/km for rural (was 44.3 g/km) • 0.808 x 48.2 = 39.0 g/km for highway (was 48.2 g/km) • CO2 calculation proceeds as normal based on the modified FC
CO2 Correction – Gasoline (2010) • Correction (%) with respect to country stats: • The difference was calculated based on this equation *Value refers to total database (all EU) due to the low number of available vehicles, reported per country
Implementation to COPERT • Euro 4 to Euro 6 • Annual correction factor (2005-2020) calculated on the basis of mean mass, capacity, CO2,TA, new registrations. Available in both: • 1753/2000/EC database • 443/2009 database • Weighted average correction factor per emission standard is calculated and used per emission standard
CO2 Correction Remarks - 1 • Large Gasoline FC increases by 10-20% due the high average capacity in the database (>3500cc). • All the other subsectors have a 10-20% decrease in FC. • The G<0.8l subsector was non-existent when the CO2 correction model was compiled • The G0.8-1.4l subsector FC average was extracted for capacity around 1390cc while the country averages are ~1250cc. • The G1.4-2l subsector FC average was extracted for capacity close to the CO2 monitoring database which can explain the smaller corrections • The FCSAMPLE was based on Euro 4 measurements so it is expected to be somewhat higher than Euro 5 cars
CO2 Correction Remarks - 2 • Diesel vehicles have much lower correction factors • D<1.4l and D1.4-2l show opposite trends; the correction was compiled with the old COPERT classification (only D<2.0l). • High capacity (D>2.0l) vehicles have very small corrections; the capacity average in this case is much closer to 2.0l (less than 2500cc)
Diesel Euro 5/6 update • Diesel Euro 5 vehicles exceed NOx emissions in real-world operation: • tuned engine and aftertreatment components only strive to achieve type approval limits • reducing fuel consumption and GHG emissions are the priority • Euro 5 testing coordinated in the framework of the ERMES activity • Representative NOx emission factors are still under development • Intermediate solution had to be found!
Diesel Euro 5/6 update • Available data show that Euro 5 is the highest light duty NOx emission technology ever • Considerably lower NOx emissions are shown for the small sample of Euro 6 cars tested, however • these models are of advanced emission control technology • it is not yet known if this technology will be used in the future • exact type-approval procedure has not been decided yet • Real-world PM levels appear consistent with the type approval reductions and current COPERT emission factors (very efficient diesel particle filters (DPFs) in all diesel cars post Euro 5)
Diesel Euro 5/6 update • Correction in COPERT will be applied to diesel NOx emission factors only • Detailed emission factors exist in COPERT for Euro 4. • Proposed reduction factors based on Euro 4: • Negative reduction factor implies an increase
Diesel Euro 5/6 update • Proposed ‘reduction factor’ will lead to a substantial increase in NOx emissions compared to the previous COPERT version • The increase will be more important to countries where the stock of Euro 5 cars is relatively more important. • Detailed emission factors for Euro 5 and Euro 6 will be made available in Spring 2013 through ERMES and will be introduced in the next COPERT version. • No big differences expected compared to v10.0
E85 medium passenger car • Bioethanol is the most widely used biofuel in the world • Compared to biodiesel, ethanol has a higher production potential due to a larger range of possible biomass sources • The most popular blend is E85 (85% ethanol and 15% gasoline by volume) • A comparison of E85 vs. E0/E5/E10 in Euro4 – Euro5 passenger cars was carried out, mostly based on a database held by AVL MTC. Study was performed within ERMES activity
Tested Fuels • Neat gasoline, with no ethanol blend, referred to as E0 • E5, consisting of standard gasoline fuel containing 5% of ethanol. • A blend of 15% gasoline and 85% ethanol, referred to as E85
Test details (Euro 4) • The Common Artemis Driving Cycle (CADC) was used for the tests • Only the ‘hot’ phase of the urban part of the cycle was considered • The ambient temperature for all tests was around 22-25 oC.
CO conclusions (Euro 4) • Significant decreases in CO by using E85 over E5 or E0 fuel. in the order of 50% collectively for the E85/E5 and E85/E0 ratios. • 59% for the E85/E5 ratio and 27% for the E85/E0 ratio • Reduction is approximately 30% at urban conditions and 65% at highway conditions
HC conclusions (Euro 4) • The overall mean when using E85 over E5 or E0 is 33% less than using gasoline alone • 42% reduction for the E85/E5 ratio, compared to 14% for the E85/E0 ratio • In urban speeds, use of E85 over E5 leads to an increase in emissions by 25% while emissions over highway conditions drop by 53%
NOx conclusions (Euro 4) • Impacts on NOx overall are negligible, with an overall increase when using E85 of 4% • The increase is limited to 1% when comparing E85 vs. E5 and 4% when comparing E85 vs. E0