# Commission Regulation (EU) 2017/2400 of 12 December 2017 implementing Regulation (EC) No 595/2009 of the European Parliament and of the Council as regards the determination of the CO2 emissions and fuel consumption of heavy-duty vehicles and amending Directive 2007/46/EC of the European Parliament and of the Council and Commission Regulation (EU) No 582/2011 (Text with EEA relevance), Division 3.1.1.7

Extent: E+W+S+N.I.

The torque dependent efficiency of the planetary range section in low range state for the special case of transmissions consisting of a countershaft-type main section in series with a planetary range section (with non-rotating ring gearwheel and the planet carrier connected to the output shaft) may, alternatively to the procedure described in 3.1.1.8., be calculated by:
ηlowrange=1+ηm,ring×ηm,sun×zringzsun1+zringzsunwhere:
ηm,ring Torque dependent efficiency of the ring-to-planet gear mesh = 99,3 % [-]
ηm,sun Torque dependent efficiency of the planet-to-sun gear mesh = 98,6 % [-]
zsun Number of teeth of the sun gearwheel of the range section [-]
zring Number of teeth of the ring gearwheel of the range section [-]
The planetary range section shall be regarded as an additional gear mesh within the countershaft main section, and its torque dependent efficiency ηlowrange shall be included in the determination of the total torque dependent efficiencies ηTg for the low-range gears in the calculation in 3.1.1.4.

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Source: https://www.legislation.gov.uk/eur/2017/2400/annex/VI/division/3/division/3.1/division/3.1.1/division/3.1.1.7 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-2400/annex-VI/division-3/division-3.1/division-3.1.1/division-3.1.1.7
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.