Document ID: chunk:federal_register_of_legislation:F2023L00129:front:0:p25
Version: federal_register_of_legislation:F2023L00129
Segment Type: other
Provision Reference: 
Character Range: 69515–72377

on the fuels declared, including any blend between the declared fuels and the relevant market fuels and standards.

              At the request of the manufacturer, the requirements set out in this paragraph shall be applied to fuels used for military purposes.

              For the purposes of subparagraph 4.6.2.(a) where the emission tests are performed for demonstrating compliance with the requirements of this Regulation, a fuel analysis report of the test fuel shall be attached to the test report and shall comprise at least the parameters specified in the official specification of the fuel manufacturer.

              4.6.3. In the case of natural gas/biomethane fuelled engines, including dual-fuel engines, the manufacturer shall demonstrate the parent engines capability to adapt to any natural gas/biomethane composition that may occur across the market. This demonstration shall be carried out according to this paragraph and, in case of dual-fuel engines, also according to the additional provisions regarding the fuel adaptation procedure set out in paragraph 6.4. of Annex 15 to this Regulation.

              4.6.3.1. In the case of compressed natural gas/biomethane (CNG) there are generally two types of fuel, high calorific fuel (H-gas) and low calorific fuel (L-gas), but with a significant spread within both ranges; they differ significantly in their energy content expressed by the Wobbe Index and in their λ-shift factor (Sλ). Natural gases with a λ-shift factor between 0.89 and 1.08 (0.89 ≤ Sλ ≤ 1.08) are considered to belong to H-range, while natural gases with a λ-shift factor between 1.08 and 1.19 (1.08 ≤ Sλ ≤ 1.19) are considered to belong to L-range. The composition of the reference fuels reflects the extreme variations of Sλ.

              The parent engine shall meet the requirements of this Regulation on the reference fuels GR (fuel 1) and G25 (fuel 2), as specified in Annex 5, without any manual readjustment to the engine fuelling system between the two tests (self-adaptation is required). One adaptation run over one WHTC hot cycle without measurement is permitted after the change of the fuel. After the adaptation run the engine shall be cooled down in accordance with
              paragraph 7.6.1. of Annex 4.

              4.6.3.1.1. At the manufacturer's request the engine may be tested on a third fuel (fuel 3) if the λ-shift factor (Sλ) lies between 0.89 (that is the lower range of GR) and 1.19 (that is the upper range of G25), for example when fuel 3 is a market fuel. The results of this test may be used as a basis for the evaluation of the conformity of the production.

              4.6.3.2. In the case of liquefied natural gas/liquefied biomethane (LNG) the parent engine shall meet the requirements of this Regulation on the reference fuels GR (fuel 1) and G20 (fuel 2), as specified in