# 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 6.2.4

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

The average efficiency of the control area shall be calculated as follows:
For SR axles:
η avr,mid speed = η 5 + η 6 2
η avr,high speed = η 8 + η 9 2
η avr,total = η avr,mid speed + η avr,high speed 2
For HR axles:
η avr,low speed = η 2 + η 3 2
η avr,mid speed = η 4 + η 5 2
η avr,total = η avr,low speed + η avr,mid speed 2
where:
ηavr,low speed average efficiency for low speed
ηavr,mid speed average efficiency for mid speed
ηavr,high speed average efficiency for high speed
ηavr,total simplified averaged efficiency for axle

---
Source: https://www.legislation.gov.uk/eur/2017/2400/annex/VII/division/6/division/6.2/division/6.2.4 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-2400/annex-VII/division-6/division-6.2/division-6.2.4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.