4. The fuel economy impact of GSI recommended gear shift points shall be determined according to the following procedure: U.K.
4.1. Determination of vehicle speeds at which GSI recommends shifting up gears U.K.
This test is to be performed on a warmed up vehicle on a chassis dynamometer according to the speed profile described in Appendix 1 to this Annex. The advice of the GSI is followed for shifting up gears and the vehicle speeds, for which the GSI recommends shifting, are recorded. The test is repeated 3 times.
Vn GSI shall denote the average speed at which the GSI recommends shifting up from gear n (n = 1, 2, …, #g) into gear n + 1, determined from the 3 tests, where #g shall denote the vehicle’s number of forward gears. For this purpose only GSI shift instructions in the phase before the maximum speed is reached are taken into account and any GSI instruction during the deceleration is ignored.
For the purposes of the following calculations V0 GSI is set to 0 km/h and V#g GSI is set to 140 km/h or the maximum vehicle speed, whichever is smaller. Where the vehicle cannot attain 140 km/h, the vehicle shall be driven at its maximum speed until it rejoins the speed profile in Figure I.1.
Alternatively, the recommended GSI shift speeds may be analytically determined by the manufacturer based on the GSI algorithm contained in the extended documentation package provided according to point 3.1.
4.2. Standard gear shift points U.K.
Vn std shall denote the speed at which a typical driver is assumed to shift up from gear n into gear n + 1 without GSI recommendation. Based on the gear shift points defined in the type 1 emission test(1) the following standard gear shift speeds are defined:
=
0 km/h;
=
15 km/h;
=
35 km/h;
=
50 km/h;
=
70 km/h;
=
90 km/h;
=
110 km/h;
=
130 km/h;
=
V#g GSI;
Vn min shall denote the minimum vehicle speed the vehicle can be driven in the gear n without stalling of the engine and Vn max the maximum vehicle speed the vehicle can be driven in the gear n without creating damage to the engine.
If Vn std derived from this list is smaller than Vn + 1 min, then Vn std is set to be Vn + 1 min. If Vn std derived from this list is greater than Vn max, then Vn std is set to be Vn max (n = 1, 2, …, #g – 1).
If V#g std determined by this procedure is smaller than V#g GSI, it shall be set to V#g GSI.
4.3. Fuel consumption speed curves U.K.
The manufacturer shall supply the type-approval authority with the functional dependence of the vehicle’s fuel consumption on the steady vehicle speed when driving with gear n according to the following rules.
FCn i shall denote the fuel consumption in terms of kg/h (kilograms per hour) when the vehicle is driven with the constant vehicle speed vi = i × 5 km/h – 2,5 km/h (where i is a positive integer number) in the gear n. These data shall be provided by the manufacturer for each gear n (n = 1, 2, …, #g) and vn min ≤ vi ≤ vn max. These fuel consumption values shall be determined under identical ambient conditions corresponding to a realistic driving situation that may be defined by the vehicle manufacturer, either by a physical test or by an appropriate calculation model agreed between the approval authority and the manufacturer.
4.4. Vehicle speed distribution U.K.
The following distribution should be used for the probability Pi that the vehicle drives with a speed v, where vi – 2,5 km/h < v ≤ vi + 2,5 km/h (i = 1, …, 28):
i | Pi |
---|---|
1 | 4,610535879 |
2 | 5,083909299 |
3 | 4,86818148 |
4 | 5,128313511 |
5 | 5,233189418 |
6 | 5,548597362 |
7 | 5,768706442 |
8 | 5,881761847 |
9 | 6,105763476 |
10 | 6,098904359 |
11 | 5,533164348 |
12 | 4,761325003 |
13 | 4,077325232 |
14 | 3,533825909 |
15 | 2,968643201 |
16 | 2,61326375 |
17 | 2,275220718 |
18 | 2,014651418 |
19 | 1,873070659 |
20 | 1,838715054 |
21 | 1,982122053 |
22 | 2,124757402 |
23 | 2,226658166 |
24 | 2,137249569 |
25 | 1,76902642 |
26 | 1,665033625 |
27 | 1,671035353 |
28 | 0,607049046 |
Where the maximum speed of the vehicle corresponds to step i and i < 28, the values of Pi + 1 to P28 shall be added to Pi.
4.5. Determination of the model fuel consumption U.K.
FCGSI shall denote the fuel consumption of the vehicle when the driver follows the advice of the GSI:
FCGSI i = FCn i, where Vn – 1 GSI ≤ vi < Vn GSI (for n = 1, …, #g) and FCGSI i = 0 if vi ≥ V#g GSI
FCstd shall denote the fuel consumption of the vehicle when standard gear shift points are used:
FCstd i = FCn i, where Vn – 1 std ≤ vi < Vn std (for n = 1, …, #g) and FCstd i = 0 if vi ≥ V#g GSI
The relative saving of fuel consumption by following the advice of the GSI of the model is calculated as:
FCrel. Save = (1 – FCGSI/FCstd) × 100 %
4.6. Data records U.K.
The following information shall be recorded:
the values of Vn GSI as determined according to point 4.1,
the values FCn i of the fuel consumption speed curve as communicated by the manufacturer according to point 4.3,
the values FCGSI, FCstd and FCrel. Save as calculated according to point 4.5.
Defined in Annex 4a of UNECE Regulation No 83, 05 series of amendments.