FTP-75The FTP-75 (Federal Test Procedure) has been used for emission certification of light duty vehicles in the U.S. Effective model year 2000, vehicles have to be additionally tested on two Supplemental Federal Test Procedures (SFTP) designed to address shortcomings with the FTP-75 in the representation of (1) aggressive, high speed driving (US06), and (2) the use of air conditioning (SC03).

The FTP-75 cycle is derived from the FTP-72 cycle by adding a third phase of 505s, identical to the first phase of FTP-72 but with a hot start. The third phase starts after the engine is stopped for 10 minutes. Thus, the entire FTP-75 cycle consists of the following segments:

1. cold start phase2. transient phase3. hot start phase.

The following are basic parameters of the cycle:

Distance traveled: 11.04 miles (17.77 km) Duration: 1874s Average speed: 21.2 mph (34.1 km/h).

Figure 1. FTP-75 Cycle

The emissions from each phase are collected in a separate teflon bag, analyzed and expressed in g/mile (g/km). The weighting factors are 0.43 for the cold start, 1.0 for the transient phase and 0.57 for the hot start phase.

The FTP-75 cycle is known in Australia as the ADR 37 (Australian Design Rules) cycle.

Heavy-Duty FTP Transient CycleThe FTP (Federal Test Procedure) heavy-duty transient cycle is currently used for emission testing of heavy-duty on-road engines in the USA [CFR Title 40, Part 86.1333]. The transient test was developed to take into account the variety of heavy-duty truck and buses in American cities, including traffic in and around the cities on roads and expressways. The FTP transient test is based on the UDDS chassis dynamometer driving cycle. The cycle includes “motoring” segments and, therefore, requires a DC or AC electric dynamometer capable of both absorbing and supplying power.

The transient cycle consists of four phases: the first is a NYNF (New York Non Freeway) phase typical of light urban traffic with frequent stops and starts, the second is LANF (Los Angeles Non Freeway) phase typical of crowded urban traffic with few stops, the third is a LAFY (Los Angeles Freeway) phase simulating crowded expressway traffic in Los Angeles, and the fourth phase repeats the first NYNF phase. It comprises a cold start after a parking overnight, followed by idling, acceleration and deceleration phases, and a wide variety of different speeds and loads sequenced to simulate the running of the vehicle that corresponds to the engine being tested. There are few stabilized running conditions, and the average load factor is about 20 to 25% of the maximum horsepower available at a given speed.

The cycle is carried out twice and the second repetition is made with a warm start after a stop of 1200 s (20 min) on completion of the first cycle. The equivalent average speed is about 30 km/h and the equivalent distance traveled is 10.3 km for a running time of 1200 s. The variation of normalized speed and torque with time is shown in Figure 1.

Figure 1. FTP Transient Cycle

The average load factor of the FTP cycle is roughly 20-25% of the maximum engine horsepower available at a given engine speed. Heavy duty diesel engines tested on the FTP cycle produce medium to high exhaust gas temperatures. Generally, the temperature is at a medium level between 250 and 350°C, but there are some hot sections with temperatures reaching as high as 450°C.

FTP-72 (UDDS)The U.S. FTP-72 (Federal Test Procedure) cycle is also called Urban Dynamometer Driving Schedule (UDDS) or LA-4 cycle [CFR 40, 86, App.I]. The same engine driving cycle is known in Sweden as A10 or CVS (Constant Volume Sampler) cycle and in Australia as the ADR 27 (Australian Design Rules) cycle. This cycle should not be confused with the UDDS schedule for heavy-duty vehicles.

The cycle simulates a urban route of 12.07 km (7.5 mi) with frequent stops. The maximum speed is 91.2 km/h (56.7 mi/h) and the average speed is 31.5 km/h (19.6 mi/h).

Figure 1. FTP-72 Cycle

The cycle consists of two phases: (1) 505s (5.78 km at 41.2 km average speed) and (2) 864s. The first phase begins with cold start. The two phases are separated by stopping the engine for 10 minutes. In the U.S. a weighting factors of 0.43 and 0.57 are applied to the first and second phase, respectively. In Sweden both phases have the same weighting factors. Emissions are expressed in g/mile or g/km.

ECE 15 + EUDC / NEDCThe ECE+EUDC test cycle is performed on a chassis dynamometer. The cycle—also known as the MVEG-A cycle—is used for emission certification of light duty vehicles in Europe [EEC Directive 90/C81/01].

The entire cycle includes four ECE segments, Figure 1, repeated without interruption, followed by one EUDC segment, Figure 2. Before the test, the vehicle is allowed to soak for at least 6 hours at a test temperature of 20-30°C. It is then started and allowed to idle for 40s.

Effective year 2000, that idling period has been eliminated, i.e., engine starts at 0 s and the emission sampling begins at the same time. This modified cold-start procedure is also referred to as the New European Driving Cycle or NEDC.

Emissions are sampled during the cycle according the the “Constant Volume Sampling” technique, analyzed, and expressed in g/km for each of the pollutants.

Figure 1. ECE 15 Cycle

The ECE cycle is an urban driving cycle, also known as UDC. It was devised to represent city driving conditions, e.g. in Paris or Rome. It is characterized by low vehicle speed, low engine load, and low exhaust gas temperature.

The above urban driving cycle represents Type I test, as defined by the original ECE 15 emissions procedure. Type II test is a warmed-up idle tailpipe CO test conducted immediately after the fourth cycle of the Type I test. Type III test is a two-mode (idle and 50 km/h) chassis dynamometer procedure for crankcase emission determination.

Figure 2. EUDC Cycle

The EUDC (Extra Urban Driving Cycle) segment has been added after the fourth ECE cycle to account for more aggressive, high speed driving modes. The maximum speed of the EUDC cycle is 120 km/h. An alternative EUDC cycle for low-powered vehicles has been also defined with a maximum speed limited to 90 km/h (Figure 3).

Figure 3. EUDC Cycle for Low Power Vehicles

The following table includes a summary of selected parameters for the ECE, EUDC and NEDC cycles.

Characteristics Unit ECE 15 EUDC NEDCDistance km 4×1.013=4.052 6.955 11.007Duration s 4×195=780 400 1180Average Speed km/h 18.7 (with idling) 62.6 33.6Maximum Speed km/h 50 120 120

ECE R49The R49 is a 13-mode steady-state diesel engine test cycle introduced by ECE Regulation No.49 and then adopted by the EEC [EEC Directive 88/77, EEC Journal Officiel L36, 8 Feb. 1988]. It had been used for type approval emission testing of heavy-duty highway engines through the Euro II emission standard. Effective October 2000 (Euro III), the R49 cycle was replaced by the ESC schedule.

The R49 test is performed on an engine dynamometer operated through a sequence of 13 speed and load conditions. Exhaust emissions measured at each mode are expressed in g/kWh. The final test result is a weighted average of the 13 modes. The test conditions and weighting factors of the R49 cycle are shown in Table 1 and in Figure 1. The areas of circles in the graph are proportional to the weighting factors for the respective modes.

The running conditions of the R49 test cycle are identical to those of the US 13-mode cycle. The weighting factors, however, are different. Due to high weighting factors for modes 6 and 8 (high engine load), the European cycle is characterized by high average exhaust gas temperatures.

Table 1ECE R49 and US 13-mode Cycles

Mode No. Speed Load, % Weighting FactorsR49 US

1 Idle - 0.25/3 0.20/32 maximum

torquespeed

10 0.08 0.083 25 0.08 0.084 50 0.08 0.085 75 0.08 0.086 100 0.25 0.087 idle - 0.25/3 0.20/38 rated

powerspeed

100 0.10 0.089 75 0.02 0.0810 50 0.02 0.0811 25 0.02 0.0812 10 0.02 0.0813 idle - 0.25/3 0.20/3

Figure 1. ECE R49 Cycle

Japanese 10 ModeThe 10 mode cycle [Japanese Industrial Safety and Health Association, JISHA 899, 1983] was used for emission certification of light duty vehicles in Japan. It has been replaced by the newer 10-15 mode cycle.

The 10 mode cycle simulates urban driving conditions. One segment of the cycle covers a distance of 0.664 km at an average speed of 17.7 km/h and lasts 135 s (Figure 1). The maximum speed is 40 km/h.

Figure 1. 10 Mode Cycle

The entire cycle begins with a 15 minutes warm-up at 40 km/h, followed by six repetitions of the same segment. Emissions are measured over the last five segments (so the emission measurement period represents a route of 3.32 km, completed in 675 s). Emissions are expressed in g/km.

Japanese 10-15 ModeThe 10-15 mode cycle is currently used in Japan for emission certification and fuel economy for light duty vehicles. It is derived from the 10 mode cycle by adding another 15-mode segment of a maximum speed of 70 km/h. Emissions are expressed in g/km [Japanese Industrial Safety and Health Association, JISHA 899, 1983].

The entire cycle includes a sequence of a 15 minute warm-up at 60 km/h, idle test, 5 minute warm-up at 60 km/h, and one 15-mode segment, followed by three repetitions of 10-mode segments and one 15-mode segment. Emissions are measured over the last four segments (3×10-mode + 1×15-mode, Figure 1).

Figure 1. 10-15 Mode Cycle

The distance of the cycle is 4.16 km, average speed 22.7 km/h, duration 660 s (or 6.34 km, 25.6 km/h, 892 s, respectively, including the initial 15 mode segment).

Japanese 13 ModeThe 13-mode cycle replaced the older 6-mode cycle for the testing of heavy duty engines in Japan.

The test includes a sequence of 13 steady-state modes. The emissions are averaged over the entire cycle using a set of weighting factors and are expressed in g/kWh. The test emphasizes low-speed driving conditions, is characterized by low average engine loads and low exhaust temperatures.

There are differences in some test modes for diesel and gasoline/LPG engines and the weighting factors are different. The test parameters for the diesel cycle are listed in Table 1, and for the gasoline cycle in Table 2.

Table 1Diesel 13 Mode Cycle

Mode Speed Load Weighting factor  % of nominal %  1 Idle - 0.410/22 40 20 0.0373 40 40 0.0274 Idle - 0.410/25 60 20 0.0296 60 40 0.0647 80 40 0.0418 80 60 0.0329 60 60 0.07710 60 80 0.05511 60 95 0.04912 80 80 0.03713 60 5 0.142

Table 2Gasoline/LPG 13 Mode Cycle

Mode Speed Load Weighting factor  % of nominal %  1 Idle - 0.314/22 40 40 0.0363 40 60 0.0394 Idle - 0.314/25 60 20 0.0886 60 40 0.1177 80 40 0.0588 80 60 0.0289 60 60 0.06610 60 80 0.03411 60 95 0.02812 40 20 0.09613 40* 20* 0.096* - deceleration to idle