smart fortwo mhd Advanced Gasoline Idle Start Stop Technology Test Results Report

Transcription

1 smart fortwo mhd Advanced Gasoline Idle Start Stop Technology Test Results Report June 2010

2 Disclaimer notice Transport Canada's ecotechnology for Vehicles program ("etv") tests emerging vehicle technologies to assess their performance in accordance with established Canadian motor vehicle standards. The test results presented herein do not, in themselves, represent an official determination by Transport Canada regarding fuel consumption or compliance with safety and emission standards of any motor vehicle or motor vehicle component. Transport Canada does not certify, approve or endorse any motor vehicle product. Technologies selected for evaluation, and test results, are not intended to convey policy or recommendations on behalf of Transport Canada or the Government of Canada. Transport Canada and more generally the Government of Canada make no representation or warranty of any kind, either express or implied, as to the technologies selected for testing and evaluation by etv, nor as to their fitness for any particular use. Transport Canada and more generally the Government of Canada do not assume nor accept any liability arising from any use of the information and applications contained or provided on or through these test results. Transport Canada and more generally the Government of Canada do not assume nor accept any liability arising from any use of third party sourced content. Any comments concerning its content should be directed to: Transport Canada Environmental Initiatives (AHEC) ecotechnology for Vehicles (etv) Program 330 Sparks Street Place de Ville, Tower C Ottawa, Ontario K1A 0N5 etv@tc.gc.ca Her Majesty in Right of Canada, as represented by the Minister of Transport,

3 Table of Contents EXECUTIVE SUMMARY INTRODUCTION TESTING PROGRAM TESTING LOCATIONS VEHICLE OVERVIEW PHASE I - LABORATORY TESTING RESULTS Cycle Fuel Consumption Results Cycle Fuel Consumption Results New York City Cycle Fuel Consumption Results Emissions Results Idling Duration Experiment PHASE II DYNAMIC TESTING ACCELERATION EVALUATION MAXIMUM SPEED IN GEAR HANDLING Lateral Skid Pad Emergency Lane Change Manoeuvre NOISE EMISSIONS TESTS BRAKING SUMMARY REMARKS REGARDING DYNAMIC TESTING PHASE III - ON-ROAD EVALUATIONS CONCLUSIONS WHAT DOES THIS MEAN FOR CANADIANS?... 31

4 EXECUTIVE SUMMARY The smart car has been one of the most fuel-efficient vehicles in the two-seater class since it was first introduced in Canada in Currently, smart models are sold with a gas engine in Canada and the United States, while the diesel model is sold in Mexico, Europe and other world markets and a fully electric model will be released in the United Kingdom in the near future. The etv program selected the smart fortwo micro hybrid drive (mhd) for testing and evaluation because of its idle start-stop system. Anti-idling or start-stop technology is designed to reduce fuel consumption and exhaust emissions during periods of urban driving. These systems are relatively rare within the Canadian market and are generally limited to vehicles that are full hybrids. Thus, the anti-idling technology, combined with the base smart s impressive fuel efficiency made the smart mhd an ideal vehicle for inclusion in the etv program. It should be noted that, despite its name and the inclusion of the idle start-stop technology, the European smart fortwo mhd is not a full hybrid. In acquiring the smart mhd, the etv program wanted to quantify the fuel savings that could result from the idle start-stop system as well as how it performed under a variety of Canadian climatic conditions, particularly in city driving and in cold weather. The vehicle was tested and evaluated over three phases: laboratory fuel consumption and exhaust emissions; dynamic track testing; and on-road evaluations. The following is a summary of the results obtained from these evaluations. Criteria Results Fuel consumption In 2-cycle testing, with the idle start-stop (eco-mode) turned ON, the fuel consumption values are 6.20 L/100 km for the city, 5.12 L/100 km for the highway and 5.71 L/100 km for combined city/highway. In all testing cycles, the use of idle start-stop offers considerable savings in fuel consumption in city driving. CO 2 emissions Testing cycle No idle With idle % savings start-stop start-stop 2-cycle % 5-cycle % NYCC % Real-world % In combined city and highway testing, with the idle start-stop (ecomode) turned ON, the smart mhd obtained an adjusted value of 137 g/km, which is 10% less than the current best performers in the sub-compact class and a 40% improvement over all models within its class. ecotechnology for Vehicles 4

5 Criteria Exhaust Emissions Idle Start-Stop Performance Results Dynamic Performance Driver Evaluations Results With regard to non-co 2 exhaust emissions, the 2009 smart mhd meets the Euro V emissions standards for which it was designed and is well below the Tier 2, Bin 5 standards in effect in Canada. The smart mhd is able to operate between -7 C and 40 C, using various combinations of the auxiliary systems. However, below -7 C, the vehicle did not allow the eco-mode to engage and turn off the engine when idling, despite acceptable battery voltage levels. This is by design of the manufacturer. Overall, handling and performance were good, pass or acceptable relative to the sub-compact class. As such, dynamic performance would not pose a barrier to its inclusion in the fleet of sub-compact vehicles in Canada. The smart mhd reached an average maximum speed of km/h in approximately 40 seconds while operating in 4 th gear. The maximum lateral acceleration was 6.3 m/s 2 for a 61 m turning circle. Emergency lane change performance is rated as good. External and internal noise levels were well below the limits set out in the CMVSS. Braking is compliant with all aspects of the CMVSS 135 standard. The majority of the evaluators reported that they were comfortable with the idle start-stop system, even in heavy traffic. In a comparison test with a smart fortwo not equipped with anti-idling technology, the smart mhd obtained significant fuel savings. With regards to general performance and handling several evaluators noted jerky shifting of the transmission as an issue. Barriers to the Introduction of Idle Start-Stop Technologies into the Canadian Market Public opinion research has generally established that fuel consumption and vehicle emissions have not traditionally been of primary importance to the Canadian consumer when shopping for a new vehicle 1. One of the principle barriers to the introduction of advanced gasoline technologies, such as idle start-stop, is overcoming the consumer s desire to minimize the initial purchase price (or sticker shock ) of a new vehicle, often at the expense of longer-term operating costs and environmental impacts. Conversely, innovative technologies that improve fuel efficiency often increase the initial purchase price of a vehicle. When confronted with the choice of paying more for advanced vehicle technologies such as idle stop-start, consumers often opt for a lower initial purchase price, unaware of the potential savings that the technology might offer. 1 Pollution Probe Barriers to Consumer Purchasing of More Highly Fuel-Efficient Vehicles: A Background Paper. ecotechnology for Vehicles 5

6 In addition, fuel consumption test procedures and vehicle ratings can under-estimate the potential real-world benefits of advanced technologies. The results outlined in this report support that point, since the 2-cycle tests under-represent the fuel savings obtained both in the urban-centred New York City Cycle driving cycle and in real-world driving. In these situations, not only does the vehicle cost more, but also there appears to be little improvement in the vehicle s published fuel consumption ratings a situation that compounds existing consumer barriers. As well, the development of codes and standards needs to keep pace with the innovation in new vehicle technologies, in order to ensure the safety, efficiency and suitability of the Canadian transportation system. The kind of testing that etv has undertaken in relation to idle stop-start technologies, for example, is essential in helping to engage industry and stakeholders in leading-edge research to support the development of new or modified codes and standards for all technologies, including advanced gasoline technologies. ecotechnology for Vehicles 6

7 1.0 INTRODUCTION The first smart car was introduced in Canada in late 2004 and sold through Mercedes- Benz dealers. Currently, in Canada, smart cars are sold only with a gas engine. A diesel model is sold in Mexico and Europe and a fully electric model is intended for release in the United Kingdom in the near future. Working in partnership with Mercedes-Benz, the etv program selected the European model smart fortwo mhd for testing because it is equipped with an innovative idle startstop system. This anti-idling technology is designed to reduce fuel consumption and exhaust emissions during periods of urban driving. Idle start-stop systems are relatively rare within the Canadian market and are generally limited to vehicles that are full hybrids. Thus, the anti-idling technology, combined with the smart s impressive fuel efficiency made the smart mhd an ideal vehicle for inclusion within the etv program. The engine found in the European smart fortwo micro hybrid drive (mhd) is a standard smart fortwo engine, equipped with start-stop technology. While its name suggests that vehicle is a micro hybrid, no additional battery pack has been added. Rather, the standard lead-acid battery has been replaced with an absorbed glass mat (AGM) battery, and the alternator and starter motor have been replaced with a belt-driven electric startergenerator. The start-stop system operates when the vehicle comes to a stop, either at a traffic light or in stop-and-go traffic. As the vehicle comes to a stop, the internal combustion engine switches off. As soon as the driver releases the brake pedal, the electric motor acts as the starter and instantly switches the internal combustion engine back on. During normal driving the electric motor behaves like a generator, providing power to recharge the AGM battery. According to manufacturer specifications, keeping idling to a minimum with this advanced technology reduces urban fuel consumption by more than 15%. 2.0 TESTING PROGRAM The testing program was designed to provide a fair assessment of the idle start-stop technology found on the smart mhd as well as the vehicle s fuel consumption, exhaust emissions and overall handling, both with the idle start-stop system turned on and turned off. The suggested tests were based on practices used by the Canadian Corporate Average Fuel Consumption (CAFC), the U.S. Environmental Protection Agency, the U.S. Department of Tranport, the International Standards Organization and the Society of Automotive Engineers (see smart fortwo mhd Test Plan for details). The smart mhd was evaluated over three distinct phases: Phase I - Laboratory fuel consumption and exhaust emissions testing Phase II - Dynamic track testing Phase III - On-road evaluations ecotechnology for Vehicles 7

8 Together, these various phases were designed to realistically assess the smart mhd s overall performance and identify any possible barriers that could adversely affect the introduction of its advanced technologies into the Canadian market. 3.0 TESTING LOCATIONS Phase I testing was performed in partnership with Environment Canada at the Emissions Measurement and Research Division (ERMD) located in Ottawa, Ontario. All testing was performed in a controlled laboratory, using a vehicle chassis dynamometer. The laboratory environment ensures that testing was completed to within ± 1 degree Celsius of the required test temperature. Vehicles are tested according to separate driving cycles and are maintained to within ± 1.5 km/h of the required speed. Additionally, since the vehicle was already in the Pacific Region for use by Transport Canada staff prior to and during the 2010 Olympic and Paralympic Winter Games, we were able to supplement Phase I testing by evaluating the vehicle at different speeds, temperatures and loads at the National Research Council (NRC) laboratories located on the University of British Columbia s campus. Phase II testing was performed at Transport Canada s test track facility in Blainville, Québec. The controlled environment was necessary to ensure that testing was performed on a gradient of ± 1%. The test track is equipped with over 25 kilometres of road, including both a high-speed and low-speed circuit, to allow for a variety of tests. Phase II testing was performed between September 15 and October 13, Tests were carried out only in weather conditions that were favourable to evaluation and testing standards. Phase III vehicle evaluations were preformed by Transport Canada staff, as well as by automotive journalists at the program s public outreach events. In addition, in partnership with Transport Canada s Olympic Planning Secretariat, the vehicle was driven by a number of inspectors before and during the 2010 Winter Games. The inspectors provided interesting insights regarding the smart mhd s performance under real-world conditions as they travelled throughout British Columbia to carry out their regular inspection duties. 4.0 VEHICLE OVERVIEW The smart fortwo mhd is classified as a two-seater sub-compact vehicle. It is equipped with a 999 cc (~1 litre), naturally aspirated, 3-cylinder engine. The vehicle is also equipped with other technologies, such as low rolling resistance tires, which help to limit fuel consumption and GHG emissions. Additionally, the moon roof is constructed of lightweight polycarbonate rather than glass, offering a 40% reduction in weight. In available documentation, the smart fortwo mhd is described as being capable of achieving 767 km on a 33-L tank of fuel, based on a European combined fuel ecotechnology for Vehicles 8

9 consumption rating of 4.3 L/100 km and producing only 103 g/km of CO 2. The specifications for the vehicle are presented in the table below. Weight 750 kg Drive Type Rear-wheel Length 2.70 m Engine In-line 3-cylinder, naturally aspirated, with idle start-stop Width 1.56 m Transmission 5-speed automatic Height 1.54 m Torque 92 Nm / 68 4,500 rpm Seating 2 Power 52 kw / 70 5,800 rpm Fuel Type Gasoline (95 Octane) Fuel Efficiency City Highway 5.1 L/100 km 3.8 L/100 km Displacement 999 cm 3 Fuel Tank Capacity 33 L Top Speed 145 km/h Driving Range 767 km (based on European driving cycles) Acceleration in 13.3 seconds Brakes (f/r) Disc / Drum CO 2 Emissions 103 g/km Drag Coefficient 0.34 Table 1: Specifications for the smart fortwo mhd This particular engine/power train model was chosen because it closely resembles an equivalent Canadian model in terms of accessories, engine displacement, power, torque and weight. In the smart fortwo mhd, the starter and alternator have been replaced by an electric starter-generator. The mhd system cuts the engine when the vehicle speed drops below 8 km/h (about 5 mph). It automatically re-starts the engine when the driver releases the brakes. Based on available information, the use of the mhd system has the potential of improving fuel consumption by as much as 15% in the city. In addition to the idle stop-start system, the smart mhd offers other environmentally friendly advanced features such as lightweight materials, which decrease fuel consumption and reduce GHG emissions and criteria air contaminants. Figure 1: smart fortwo mhd ecotechnology for Vehicles 9

10 The user can control the idle start-stop system by switching the eco-mode button ON or OFF. While the system is switched off, the vehicle will idle at all stops. If the driver chooses the ON position, however, the idle start-stop system will engage when the vehicle is idling, shutting off the motor. A picture of the smart mhd belt-driven idle startstop system is provided below. Figure 2: smart mhd Belt-Driven Idle Start-Stop System 5.0 PHASE I - LABORATORY TESTING More than 3,500 kilometres of vehicle and engine use were accumulated on the smart mhd, in keeping with the Code of Federal Regulations (CFR) mileage accumulation procedure. The procedure outlines the prescribed route that the vehicle must follow, using commercially available gasoline fuel with an octane rating of 91 or higher. Once mileage accumulation was completed, the vehicle was soaked 2 at a laboratory temperature for no less than 8 hours before testing began. This is to ensure that the vehicle s test temperature is controlled for comparison against other test vehicles undergoing the same emissions and fuel consumption evaluations. Emissions and fuel consumption tests were performed, as per the standard CFR procedures. Evaluations were performed over the six duty cycles listed in Table 2. Each set of tests was performed with the eco-mode engaged and disengaged (denoted as ON and OFF), for comparative analysis. 2 To soak a vehicle means to park it in the test chamber with the engine turned off and allow the entire vehicle, including engine, fluids, transmission and drive train, to reach the test cell temperature prior to the beginning of a test. ecotechnology for Vehicles 10

11 Test Parameter Testing Standard Number of Tests (Cell Temperature) Location Urban Driving U.S. FTP-75 4 (25 C) ERMD (Ottawa, ON) Cold Test U.S. FTP-72 2 (-7 C) ERMD (Ottawa, ON) Aggressive Driving US06 (SFTP) 2 (25 C) ERMD (Ottawa, ON) Highway Driving U.S. HWFET 4 (25 C) ERMD (Ottawa, ON) Electrical Load US SC03 2 (25 C) ERMD (Ottawa, ON) Stop-and-Go Driving US NYCC 4 (25 C) ERMD (Ottawa, ON) Table 2: Chassis Dynamometer Test Schedule The vehicle was mounted on a chassis dynamometer where the rear (drive) wheels were allowed to roll against a resistance drum. The drum s resistance was pre-programmed, using the vehicle s road load force parameters. Parameters and coefficients were based on a vehicle travelling from a speed of 115 km/h to 15 km/h (71.5 mph to 9.3 mph) while coasting. The final result was a model for road load force as a function of speed, during operation on a dry, level road, under reference conditions of 20 C (68 F) and 98.2 kpa (29.0 in-hg), with no wind or precipitation and with the transmission in neutral. ERMD collected and analyzed exhaust emissions for each of the duty cycles listed in Table 2. The emissions data were analyzed for: carbon monoxide carbon dioxide total hydrocarbons nitrogen oxides 5.1 RESULTS The fuel consumption estimate for the smart fortwo mhd is based on calculations for both the 2-cycle city and highway driving cycles and the 5-cycle city, highway, cold test, aggressive driving and electrical load driving cycles. The test cycles are derived from extensive data on real-world driving conditions, such as driving activity, trip length and stopping frequency, among other factors. The 2-cycle calculation is the total result of the urban driving cycle (U.S. FTP-75) and the highway duty cycle (U.S. HWFET), using a ratio of 55% city to 45% highway. The cycles are then adjusted upward 10% and 15% respectively to account for real-world differences between the way vehicles are driven on the road and over the test cycles. The end result is a combined fuel consumption rating for the vehicle in addition to separate city and highway results. These are the procedures followed by Natural Resources Canada to determine the values that are published in their annual Canadian Fuel Consumption Guide. ecotechnology for Vehicles 11

12 The 5-cycle test method is used to supplement the Canadian 2-cycle test method. It takes into account several factors that affect fuel consumption but are not addressed in the current Canadian standard. The U.S. Environmental Protection Agency began to implement 5-cycle testing in The 5-cycle method includes actual testing over a wider range of driving patterns and temperature conditions than those tested under the current Canadian standard. For example, in the real world, vehicles are often driven more aggressively, at higher speeds and with greater rates of acceleration demand placed on the engine than existing city and highway test cycles can duplicate. The US06 aggressive driving cycle takes this into account. Furthermore, drivers often use air conditioning in warm and/or humid conditions. In the 2-cycle calculation, this factor is not taken into consideration, since the test does not allow the air conditioning system to be turned on. The US SC03 test cycle reflects the added fuel needed to operate the air conditioning system. As well, given Canada s climate, a typical vehicle will be driven below 0 C (~32 F) on a fairly regular basis. The current 2-cycle testing is conducted only at 25 C (~ 77 F). The U.S. FTP-72 cold test cycle (-7 C/~ 20 F) is used to reflect the additional fuel needed to start and operate an engine at lower temperatures. Using the 5-cycle method, therefore, seems to offer a more accurate representation of the vehicle s fuel consumption and overall performance than the 2-cycle method. However, both methods apply some adjustment factors to take into account other real-world driving factors such as road grade, wind, low tire pressure and fuel quality. Because it takes other factors into account, for the same make and model, the 5-cycle method usually yields fuel consumption values that are approximately 10 to 20% higher than those obtained using the 2-cycle method Cycle Fuel Consumption Results The smart fortwo mhd was tested twice against the FTP-75 city cycle and the HWFET highway cycle, both with eco-mode ON and with eco-mode OFF, according to current Canadian standards for fuel consumption testing. The results were averaged for each cycle. The results for the fuel consumption of the smart fortwo mhd with the eco-mode ON, based on the 2-cycle calculations (adjusted 10% and 15% respectively) are 6.20 L/100km for the city and 5.12 L/100km for the highway. An adjusted combined fuel consumption value, using a 55% and 45% weighting for the city and highway respectively, is 5.71 L/100km. With the eco-mode turned OFF, the adjusted 2-cycle calculations offer a fuel consumption of 6.45 L/100km for the city. Therefore, driving with the eco-mode turned on resulted in a 5%-savings in fuel in the city. It should be noted, however, that higher savings are possible, as the FTP-75 city cycle offers 23 stops, though their duration is quite short (< 5 seconds) in most cases. Therefore, the system s full fuel savings are not entirely reflected through this particular cycle. The resulting combined fuel consumption ecotechnology for Vehicles 12

13 value, adjusted using a 55% and 45% weighting for the city and highway respectively, becomes 5.89 L/100 km. 2- Cycle Fuel Consumption (L/100km) Adjusted Values City Highway Combined City Savings Eco-mode OFF Eco-mode ON % Table 3: Adjusted 2-Cycle Fuel Consumption Values Figure 3 below shows the unadjusted 3 2-cycle combined fuel consumption value of 5.14 L/100 km versus the fleet average for model year 2009, as well as the Canadian (CAFC) and U.S. (CAFE) standards. It can be seen that the smart fortwo mhd is more than 40% below the 2009 model year CAFC standard of 8.60 L/100 km and more than 26.5% below the actual fleet average achieved by all new cars in Vehicle Footprint Vs Fuel Consumption CAFE/CAFC - Cars 12,0 10,0 Fuel Consumption (L/100 km) 8,0 6,0 4,0 2,0 US Canada Fleet Average Target Smart mhd 0,0 0,0 10,0 20,0 30,0 40,0 50,0 60,0 70,0 80,0 Vehicle Footprint (square feet) Figure 3: Unadjusted Fuel Consumption against Canadian and U.S. Standards Cycle Fuel Consumption Results Each of the 5-cycles is divided into phases also referred to as bags because each phase sample is bagged and analyzed separately, without interruption, during the test. 3 Fuel consumption standards are compared to unadjusted values in both Canada and the U.S. Adjusted values are used for labelling purposes only. ecotechnology for Vehicles 13

14 The following equations are derived from 40 CFR Parts 86 and 600, to determine both the city and highway fuel economy 4 results for a vehicle. Where: Bag # FE is the fuel economy in US miles per gallon of fuel during the specified bag of the FTP test conducted at an ambient temperature of 75ºF or 20ºF Under the vehicle specific 5-cycle formula, the highway fuel economy value would be calculated as follows: 4 The term fuel economy is used here to reflect the fact that 5-cycle testing is a U.S. standard and not the Canadian standard. In Canada, the term fuel consumption is used. ecotechnology for Vehicles 14

15 The results for the fuel consumption of the smart fortwo mhd, based on the 5-cycle calculations above, are 7.10 L/100 km for the city and 6.22 L/100 km for the highway, with the eco-mode ON. When the eco-mode ON values are compared to the eco-mode OFF values for 5-cycle testing, the eco-mode ON offers a 5% fuel savings in city driving. 5- Cycle Calculated Vehicle Specific Fuel Consumption (L/100km) City Highway Combined City Savings Eco-mode OFF Eco-mode ON % Table 4: 5-Cycle Fuel Consumption Values Although these fuel consumption values are higher than those obtained during the 2-cycle testing, the 5-cycle testing values provide a more accurate representation of what a driver can expect in terms of real-world fuel consumption. When compared against the city and highway values for the 2-cycle calculation, the 5-cycle fuel consumption values are 13% and 18% higher for city and highway driving respectively New York City Cycle Fuel Consumption Results The New York City Cycle (NYCC) is a standard emissions cycle developed by the U.S. Environmental Protection Agency (EPA). This cycle is not used for emissions or fuel consumption regulations for light-duty vehicles. However, the NYCC cycle is often used in hybrid vehicle research, to help determine the effective range of a hybrid vehicle in ecotechnology for Vehicles 15

16 city stop-and-go traffic. This cycle was used with the smart fortwo mhd because it offers a more accurate representation of city driving, with quick accelerations from a start and longer periods of idling. The cycle was run twice with the idle start-stop system engaged and twice with it disengaged, with the results averaged for each mode. NYCC Fuel Consumption (L/100km) City City Savings Eco-mode OFF Eco-mode ON % Table 5: New York City Cycle Fuel Consumption Values As the results in the table above demonstrate, the smart fortwo mhd offers an 11.5% savings in fuel in the laboratory when tested against the NYCC. Although, the laboratory offers a well-controlled environment, its simulated real-world driving yields slightly different results than those presented in the previous sections. It can be inferred from the results presented that the standard fuel consumption cycles (both the Canadian 2-cycle and the U.S. 5-cycle) may under-estimate the full fuel savings potential of an idle start-stop system. The stops in these cycles are limited in number and very short (less than 5 seconds). The NYCC, with longer stop periods that are more consistent with real-world driving conditions, demonstrates results that are 7% better than the current regulated cycles. The etv program will continue to work with stakeholders, inlcuding government and industry, on better ways to demonstrate the full benefits of the idle start-stop technology Emissions Results The results of the city and highway test cycles offer an adjusted combined CO 2 emissions value of 137 g/km. The two best performing comparable sub-compact vehicles for the same model year, currently available on the Canadian market, obtained CO 2 emissions value of 152 g/km CO 2. Thus, technologies such as those found in the smart mhd could offer a 10% reduction in CO 2 emissions over the current best performers in the subcompact class. When compared to the national average of all sub-compact cars available in Canada, the CO 2 emissions reported for the same model year are 238 g/km. The smart mhd, therefore, offers a 40% improvement in CO 2 emissions over all models within its class. With regard to non-co 2 exhaust emissions, the 2009 smart mhd meets the Euro V emissions standards for which it was designed. Additionally, the smart fortwo mhd is well below the Canadian emission standards against which it was tested. ecotechnology for Vehicles 16

17 Mode CO NMHC HCHO NOx CO 2 smart mhd eco-mode OFF smart mhd eco-mode ON Standard Bin Euro 5 Emissions Table 6: Federal Test Procedure 75 - Exhaust Emissions vs. Standards (g/mile) It should be noted that the values for non-methane hydrocarbons were slightly higher in both tests on the FTP-75, with the eco-mode engaged. Although still well below the limit established both in Canada and in Europe, the engine restarts may be causing this slight increase. There may be some small residence time effect within the exhaust sampling system that negatively assesses anti-idling systems but any such effect should be very minor to the point of being difficult to quantify Idling Duration Experiment Although it was not included in the original test plan, the etv program performed additional steady-state dynamometer tests at the NRC s environmental chamber, located at the Institute for Fuel Cell Innovation in Vancouver, British Columbia. The test cell can simulate extreme temperatures, humidity, altitude and atmospheric conditions for evaluating clean energy technologies under steady dynamometer load settings. The testing was performed in partnership with the NRC s testing staff as well as an Environment Canada field test team from ERMD. ecotechnology for Vehicles 17

18 Figure 4: smart mhd on Dynamometer at NRC Fuel Cell Institute The smart mhd was evaluated at 5% humidity at temperatures ranging from -10ºC to 40ºC. The object of this experiment was to address concerns from Canadians regarding the performance of auxiliary systems and the ability of the start-stop system to function at cold and warm temperatures. The test procedure does not reflect any existing or proposed standard but does follow general procedures and practices normally associated with dynamometer testing and exhaust emissions analysis. Testing involved soaking the smart mhd at an initial temperature of -10ºC, after which the vehicle was driven against the resistance of the drums until the eco-mode was engaged (ON) 5 and with various combinations of auxiliary systems in use. The vehicle was slowed to a stop and allowed to remain at a standstill (anti-idle) for as long as possible. Table 7 below summarizes the findings. Cell Temperature (Celsius) Auxiliary Devices In Use Anti-Idle Duration Notes -10 Heater / Radio / Headlights 0 Minutes -7 Heater / Radio / Headlights 53 Minutes System did not engage at this temperature System engaged, cabin temperature begins to drop after 5 minutes 0 Heater / Radio / Headlights > 15 Minutes System engaged 10 Radio / Headlights > 15 Minutes System engaged 20 Radio / Headlights > 15 Minutes System engaged Air Conditioning / Radio / Headlights Air Conditioning / Radio / Headlights > 15 Minutes System engaged > 15 Minutes Table 7: Idle Stop-start Performance Results System engaged, cabin temperature begins to warm after 4 minutes The experiment demonstrated that the smart mhd is able to operate between a temperature of 7ºC and 40ºC, while using various combinations of the auxiliary systems. However, below -7 C, the vehicle would not allow the eco-mode to engage and turn off the engine, despite acceptable battery voltage levels. This 7 C cut-off is intentional. The manufacturer deems the heating requirement below 7 C to be such that the system would be repeatedly engaging and disengaging to the point of offering little in the way of fuel savings. Initially, we began testing the system to gauge the length of time during which it would remain off before the engine was forced to turn on. During the 7ºC trial, the vehicle was 5 The eco-mode system will not engage on a cold start. Often, a few minutes of driving are required, depending on the ambient temperature, before the system will engage. ecotechnology for Vehicles 18

19 anti-idling for 53 minutes before the engine came on. Given our time constraints and that most stops on Canadian public roads in traffic are less than 5 minutes, we tested for approximately 20 minutes at each subsequent temperature, and reported successful antiidle periods greater than 15 minutes. During all trials where the system was engaged, the idling system and the auxiliary accessories remained on. The only noticeable difference was that, at cold and very hot temperatures, the heater and the air conditioning began to blow either colder or warmer air, depending on the temperature outside the vehicle. Lastly, the idle start-stop system is controlled by the engine control unit (ECU), which monitors the battery voltage. When the battery is approaching its cut-off voltage, the idle start-stop system turns the engine on and the system remains on standby as the battery recharges. Thus, the ECU ensures that the vehicle does not turn off the engine when the battery cannot supply enough current to restart the engine and/or power the auxiliary accessories. 6.0 PHASE II DYNAMIC TESTING The smart fortwo mhd underwent dynamic and performance testing in September and October Most aspects of the tests performed were for general dynamic assessment purposes and not as a measure of compliance with the Canada Motor Vehicle Safety Standards (CMVSS). Concerns about fuel-efficient vehicles are not always limited to exhaust emissions and greenhouse gas reduction. The general dynamic testing was performed because the etv program wished to assess how well smaller, more fuelefficient vehicles function in various road situations, with a view to identifying any possible issues. As mentioned previously, the dynamic testing was performed at Transports Canada s test facility in Blainville, Québec. An aerial view of the test track is provided below. Figure 5: Dynamic Test Track Facility Overview ecotechnology for Vehicles 19

20 6.1 ACCELERATION EVALUATION The maximum acceleration was determined by starting the vehicle from a standing start and following the procedure set out below. 1. The vehicle was evaluated by accelerating to the maximum attainable speed in a quarter of a mile (402.3 m). 2. The vehicle was evaluated by accelerating to the maximum attainable speed in a kilometre (1000 m). Shifting occurred at what was determined to be an optimal shift point. To account for variations in wind, the vehicle was driven in both directions on the test track, with the results averaged. Distance Speed ( km/hr ) 1/4 mile ( m) 106 1,000 m 134 Table 8: Average Speed Results for Specified Distances 6.2 MAXIMUM SPEED IN GEAR The maximum speed attainable was tested and recorded for each gear. The driver started from a standing start for first gear only. The vehicle was accelerated, changing gears only when the vehicle engine speed reached its maximum peak rpm for at least 3 seconds. The maximum speed and revolutions per minute was recorded for each gear. Since speed is affected by wind, tests were performed in both directions and averaged. Tests took place on October 13, 2009 and the recorded wind speed was 11 km/h. Table 9 lists the maximum speeds obtained in two separate trials in opposite directions for each gear. Vmax Gear selection (km/h) A. Gear selection no B. Gear selection no C. Gear selection no D. Gear selection no E. Gear selection no Table 9: Average Results for Maximum Speed in Each Gear During testing, the smart mhd reached an average maximum speed of km/h in approximately 40 seconds, while operating in 4 th gear. Thus, the smart mhd has the capability of meeting and exceeding all minimum speed requirements on public roads in Canada. Additionally, the torque and acceleration compare favourably to typical results ecotechnology for Vehicles 20

21 in the sub-compact class, and allow for the highway merging and overtaking that most Canadians have come to expect from their vehicles. Figure 6 below presents the maximum speed and speed in each gear in one direction before being averaged th 138 km/h rd km/ h km/h 5 th Speed (km/h) st 2 nd 78 km/ h km/h Time (seconds) Figure 6: Maximum Speed in Gear, Single Run 6.3 HANDLING Lateral Skid Pad The lateral skid pad test was used to determine the maximum speed that the smart mhd could achieve in a cornering situation. When a vehicle reaches its cornering limit, it will either under-steer or over-steer, losing traction on the curve. When the vehicle has almost lost traction, the maximum lateral acceleration is recorded. In order to measure vehicle displacement, speed and lateral acceleration, the smart mhd was equipped with a combined GPS and accelerometer-based data acquisition system. All measurements refer to the vehicle s centre of gravity. Tires were warmed up and conditioned by using a sinusoidal steering pattern at a frequency of 1 Hz, a peak steering-wheel angle amplitude corresponding to a peak lateral acceleration of g, and a speed of 56 km/h. The vehicle was driven through the course four times, performing 10 cycles of sinusoidal steering during each pass. ecotechnology for Vehicles 21

22 Testing was performed under the following conditions: The vehicle was equipped with new tires. Tire pressure was adjusted to conform to the manufacturer s recommendations. The vehicle s weight was adjusted to its lightly loaded condition. The skid pad was 61 m in diameter. Figure 7: Test Vehicle on Counter-Clockwise Run The results presented in Table 10 show that the maximum speed that the vehicle can achieve in a cornering situation is 51 km/h. Clockwise Counter-Clockwise Speed (km/h) Stay Inside Corridor? (Yes/No) Speed (km/h) Stay Inside Corridor? (Yes/No) 50/51 Yes 50/50 Yes 53/52 Yes 55/51(*) Yes 62/51(*) Yes 57/51(*) Yes 53/51(*) No *ESC system is activated, reducing speed to 51 km/h Table 10: Skid Pad Test Results Even when the cruise control is engaged, the maximum speed that the vehicle can achieve in a cornering situation, with the electronic stability control (ESC) system turned on, is still 51 km/h. In this case, the maximum lateral acceleration is 6.3 m/s 2, based on a peak friction coefficient of 98. The coefficient value is dependent on several factors that make it almost impossible to predict the friction forces (magnitude and direction between tires and the test surface). This complex phenomenon depends on a tire longitudinal/lateral motion and will not be discussed here. ecotechnology for Vehicles 22

23 a 1 = 6.3 m/s 2 Because the ESC system engaged, the vehicle never reached its cornering limit and never lost traction. It can therefore be concluded that the ESC system on the smart mhd is effective in helping to maintain vehicle stability in a cornering situation and, by extension, in most road situations Emergency Lane Change Manoeuvre The emergency lane change manoeuvre with obstacle avoidance test was performed, based on ISO : 2002 Passenger Cars Test Track for a severe lane change manoeuvre. During this test, the vehicle entered the course at a particular speed and the throttle was released. The driver then attempted to negotiate the course without striking the pylons. The test speed was progressively increased until instability occurred or the course could not be negotiated. Figure 8: Emergency Lane Change Course As illustrated in Figure 8, section 4 of the course was shorter than section 2 by one metre in order to achieve maximum lateral acceleration at this area. Tests were performed in one direction only. If any pylons were hit, the run was disallowed. ecotechnology for Vehicles 23

24 Figure 9: Emergency Lane Change Manoeuvre, Disallowed Run Several tests were necessary to determine at which speed the smart mhd was able to negotiate all the way through the prescribed course without hitting a pylon. Table 11 lists all runs in increasing order, by speed. Initial Speed (km/h) Pylon Hit? (Yes/No) 50 No 55 No 60 No 59 No 63(*) No 65 No 67 No 70(**)/60 Yes *First occurrence of electronic stability control (ESC) system engagement **ESC controlled vehicle s behaviour, average speed dropped to 60 km/h Table 11: smart fortwo mhd Emergency Lane Change Results While there is no pass or fail in terms of speed for emergency lane change manoeuvres, it is a fair assessment of the lateral stability of a vehicle. The maximum successful entry speed through the course was recorded as 67 km/h. This result is fair compared to other vehicles that the etv program has tested. ecotechnology for Vehicles 24

25 10 8 Run 50 (km/h): -7.8 m/s2 Run 70 (km/h): -9.0 (m/s2) Lateral Acceleration (m/s 2 ) ,5 1 1,5 2 2,5 3 3,5 4 Time (seconds) Figure 10: Lateral Accelerations Recorded During Emergency Lane Change Manoeuvre As seen in Figure 10 above, the maximum lateral acceleration recorded on a successful run was 9.0 m/s NOISE EMISSIONS TESTS The smart mhd was tested in accordance with the CMVSS 1106 Noise Emissions Test, SAE Recommended Practice J986, Sound Level for Passenger Cars and Light Trucks, and SAE Standard J1470, Measurement of Noise Emitted by Accelerating Highway Vehicles. In order to measure noise emitted from the engine and exhaust, microphones were set up as shown in Figure 11 below. ecotechnology for Vehicles 25

26 Figure 11: Noise Emissions Setup Testing was performed under the following conditions: The vehicle test weight, including driver and instrumentation, did not exceed the vehicle s curb weight by more than 125 kg; For a period of one minute, the vehicle s engine speed was returned to idle and the vehicle s transmission was set in neutral gear before each run, in order to stabilize the initial transmission and exhaust system temperatures. The test procedure for the acceleration tests was as follows: When the vehicle approached a speed of 48 km/h ± 1.2 km/h, the approaching speed was stabilized before the acceleration point; At the acceleration point (± 1.5 m), as rapidly as it was possible to establish, the throttle was opened wide; Acceleration continued until the entire vehicle had exited the test zone; The sound meter was set to fast db(a). The deceleration tests followed the same procedure as above, with one modification at the deceleration point, the vehicle was returned to its idle position until it was equal to one half of the approaching speed or until the entire vehicle had exited the test zone. Results from all tests show that the ambient noise levels are within the limits of the CMVSS 1106 standards. Due to the logarithmic nature of the decibel scale, a level of 65 db is significantly lower than the 93.8 decibel limit. Generally 60 db is considered to be the level of normal human conversation while 90 db would be the sound generated by a typical lawn mower. ecotechnology for Vehicles 26

27 The levels measured for the smart mhd are typical for a gasoline powered sub-compact vehicle. Most of the noise being generated from the vehicle at these test speeds is due to tire and wind resistance, which is acceptable and similar across any vehicle power train platform. Test Side # Approaching Speed (km/h) Approaching RPM End Speed (1) (km/h) RPM max (1) Noise Level db (A) Calibration db (A) Right Right Right Right Average Left Left Left Left Average Results = Highest Average 2dB 65.5 Ambient Noise (2) 41.7 Table 12: External Noise, Approaching 48 km/h Results : Pass Test Side # Approaching Speed (km/h) Approaching RPM End Speed (1) (km/h) RPM max (1) Noise Level db (A) Calibration db (A) Right Right Right Right Average Left Left Left Left Average Results = Highest Average 2dB 62.6 Ambient Noise (2) 41.7 Table 13: External Noise, Approaching 54 km/h Results : Pass Interior noise emitted from the vehicle was evaluated at different constant speeds in order to determine the levels experienced by the driver of the vehicle. It is interesting to note that, except for idling, the smart mhd experienced a higher db within the vehicle than the values recorded externally. The interior noise levels, while well below the legal limit, were slightly higher than other sub-compact cars evaluated by etv. ecotechnology for Vehicles 27

28 Test # and Targeted Calibration Noise Level Transmission Selection Test Speed db (A) db (A) Idle Neutral Ambient Temperature 37.0 Engine Off Full Acceleration sec. 138 km/h redline Full Acceleration sec. 138 km/h redline Full acceleration sec. 138 km/h redline Average sec. 138 km/h redline 110 km/h Overdrive 110 km/h Overdrive 110 km/h Overdrive Average 77.0 Overdrive 100 km/h Overdrive 100 km/h Overdrive 100 km/h Overdrive Average 76.6 Overdrive 80 km/h th 80 km/h th 80 km/h th Average th 50 km/h rd 50 km/h rd 50 km/h rd Average rd Table 14: Internal Noise 6.5 BRAKING Testing was performed in accordance with the procedures set out in CMVSS Light Vehicle Brake Systems. The results are presented in Table 15. Test Description Pass / Fail Cold Effectiveness Pass High Speed Effectiveness Pass Stops with Engine Off Pass Failed Antilock Pass Hydraulic Circuit Failure Pass Power Brake Unit Failure Pass Parking Brake Pass Hot Performance Pass Recovery Performance Pass Table 15: Brake Test Results Summary The smart mhd is compliant with all aspects of the CMVSS 135 standard. Figure 12 below displays a sample of the stopping distances at two compliance speeds. The performance of the smart mhd at both speeds is exemplary. It should be noted that it is typical for all vehicles to exceed the high-speed braking standard by a greater relative ecotechnology for Vehicles 28

29 amount than the low-speed braking standard. This is partially due to the difficulty in applying maximum braking pressure at the start of the brake test. 30 m 40 m 50 m 60 m 70 m 80 m 90 m 100 m 110 m 120 m m at 100kph (Dry Conditions) m at high speed 112kph (Dry Conditions) 70.0 m Regulated braking limit at 100kph (Dry Conditions) m Regulated braking limit at 112kph (Dry Conditions) Figure 12: smart mhd Braking Performance 6.6 SUMMARY REMARKS REGARDING DYNAMIC TESTING Overall, the dynamic test results show that the smart mhd meets the relevant Canadian standards. All aspects of its handling and performance were either good, pass or acceptable relative to the sub-compact class, and its dynamic performance was similar to that of market competitors in its class. In addition, the vehicle met all aspects of CMVSS noise and braking standards. 7.0 PHASE III - ON-ROAD EVALUATIONS The etv engineering team and Transport Canada staff evaluated the smart mhd on the streets of Ottawa, Ontario. Drivers were asked fill-in a short two-page questionnaire and provide comments on any aspect of the smart s handling, performance or design. Evaluators reported that they were comfortable with the idle start-stop system, even in heavy city traffic. Some users noticed a slight vibration as the vehicle began to restart and noticed that the instrument panel lighting would dim slightly upon restarting. Most users were interested in exploring further the fact that this technology could be included in the purchase price of a vehicle for about $700 to $1000. With regards to general performance and handling several evaluators noted jerky shifting of the transmission as an issue. Some users wondered if turning off an engine not equipped with an idle start-stop system could offer the same savings. While similar savings might be obtained by turning off the engine in a regular vehicle, it is not really designed for multiple restarts and could damage the engine. The smart mhd s engine, on the other hand, is specifically designed to handle multiple restarts. As well, the ECU monitors the state of the battery. When too many restarts occur in a short period and/or the accessory load demands on the battery approach its cut-off voltage, the smart mhd remains in eco-mode but shifts to standby as it recharges the battery, thus preventing any chance that the engine will shut off and not be able to restart. ecotechnology for Vehicles 29

30 The etv fleet includes both a Canadian-compliant smart fortwo and the European smart mhd, providing an opportunity to compare the fuel consumption for the two vehicles on the mileage accumulation route. The route is a pre-determined path through the city that includes approximately 60 km of city driving and 28 km of highway driving. The same driver drove vehicles at the same time of the year. In the case of the smart mhd, the ecomode was engaged (ON) for the duration of the accumulation. Beginning with a full tank of fuel, the driver repeated the route until 3,500 km had been accumulated on each of the two vehicles. At each fuel fill-up, the mileage and the amount of fuel were recorded. Real-World Fuel Consumption (L/100km) Total Consumption City Savings Standard smart 5.18 smart mhd % Table 16: Real-world Fuel Consumption Results As can be seen from the real-world data presented in Table 16, a significant fuel savings (9.7 %) was obtained when using the idle start-stop system. The data is consistent and correlates well with the fuel consumption testing results for city driving cycles, as reported in Section 5 of this report. Considering all of the possible variables in the real world, such as traffic, time stopped at lights, varying speeds, wind and weather, a noticeable savings accrued that is outside of the margin of error for this idle start-stop system. Assuming 20,000 km of annual city driving, the smart mhd could offer upwards of 240 kg of CO 2 savings 6 or 1.2 kg CO 2 per 100 km when compared to a smart not equipped with the idle start-stop system. 8.0 CONCLUSIONS The etv program selected the smart fortwo micro hybrid drive (mhd) for testing and evaluation largely because of its idle start-stop system. The testing program was designed to assess the vehicle s idle start-stop technology as well as its fuel consumption, exhaust emissions and overall handling. We found that, in all testing cycles, the use of idle start-stop offers considerable savings in fuel consumption in city driving, ranging from a 4% savings in 2-cycle testing through to a savings of 11.5% with the New York City Cycle. Reduced fuel consumption with the idle start-stop technology results in reduced CO 2 emissions. In fact, with the idle start-stop (eco-mode) turned ON, the smart mhd obtained a value of 109 g/km, which is 29% less than the current best performers in the sub-compact class and a 55% improvement over all models within its class. With regard to non-co 2 exhaust 6 Calculation based on 10,000 km of city driving, assuming 2.4 kg CO 2 per litre of gasoline ecotechnology for Vehicles 30