UN R24 Supplement 4 (03 series) · UNECE Regulation No. 24 (ECE R24) — Uniform provisions concerning: I. The approval of compression ignition (C.I.) engines with regard to the emission of visible pollutants II. The approval of motor vehicles with regard to the installation of C.I. engines of an approved type III. The approval of motor vehicles equipped with C.I. engines with regard to the emission of visible pollutants by the engine IV. The measurement of power of C.I. engine.
UN R24 — Supplement 4 to the 03 series of amendments
Supplement 3 → 4
- What changed
- The fuel used must be the one available on the market; in any case of dispute, it must be the reference fuel (Annex 4).
- If a turbo-charged engine has a system compensating ambient temperature and altitude, αa or αd must be set to 1 at the manufacturer's request.
- Why
- The proposal aims to align the provisions of the 03 series of amendments to UN Regulation No. 24 with UN Regulation No. 85.
- The proposal says that the requirement to use reference fuel leads to an unjustified test additional to that in UN Regulation No. 85.
Q1What changed3 changes
Fuel (Annex 4, para. 3.2.)
The fuel used must now be the one available on the market. In any case of dispute, the fuel must be the reference fuel whose specifications are given in Annex 6. Before, the text said that the fuel must be the reference fuel whose specifications are given in Annex 6.
Correction factor for turbo-charged engines (Annex 4, para. 3.3.3.; Annex 10, para. 6.4.3.)
New paragraph 3.3.3. in Annex 4 and new paragraph 6.4.3. in Annex 10 have the same text. This text applies when a turbo-charged engine is fitted with a system which allows compensating the ambient conditions temperature and altitude. Then, at the request of the manufacturer, the correction factor αa or αd must be set to the value of 1.
Q2Why it changed
- Proposed by
- Expert from the International Organization of Motor Vehicle Manufacturers
- Working party
- GRPE, 77th session (June 2018)
Reasons
The proposal aims to align the provisions of the 03 series of amendments to UN Regulation No. 24 with UN Regulation No. 85.
Source
“to align the provisions of the 03 series of amendments to UN Regulation No. 24 with UN Regulation No. 85”
Annex 4 describes the opacity test over the full load curve of a compression ignition engine. For the determination of the engine power, the same correction factors are applied as in UN Regulation No. 85. However, the paragraph mentioned above is missing in UN Regulation No. 24. UN Regulation No. 24 should be adjusted to harmonize both Regulations.
Sources (3)
“Annex 4 of Regulation No. 24 describes the opacity test over the full load curve of a compression ignition engine.”
“For the determination of the engine power the same correction factors are applied as in UN Regulation No. 85. However, the paragraph mentioned above is missing in UN Regulation No. 24.”
“UN Regulation No. 24 should be adjusted to harmonize both Regulations.”
The requirement to use reference fuel in UN Regulation No. 24 leads to an unjustified test additional to that in UN Regulation No. 85. This requirement should therefore be harmonized.
Source
“The requirement to use reference fuel in UN Regulation No. 24 leads to an unjustified test additional to that in UN Regulation No. 85. This requirement should therefore be harmonized.”
Document trail
- 2018-03ProposalECE/TRANS/WP.29/GRPE/2018/19Proposal by the expert from OICA
- —Working party adoptsECE/TRANS/WP.29/GRPE/77GRPE session report, para. 38
- 2018-08Sent to WP.29ECE/TRANS/WP.29/2018/143Text that GRPE adopted and sent to WP.29 and AC.1
- 2018-11WP.29 adoptsECE/TRANS/WP.29/1142Adopted at the 176th session (session report, para. 172)
- 2019-05-28In forceC.N.250.2019.TREATIES-XI.B.16.24UN depositary notification
Q3Who is affected
Vehicle manufacturer
- For turbo-charged engines with a system which allows compensating ambient temperature and altitude, consider requesting αa or αd = 1.
Component supplier
- No direct action for this role.
Technical service / Approval authority
- Test with the fuel available on the market; in any case of dispute, use the reference fuel of Annex 6.
- Set αa or αd to 1 on manufacturer request for turbo-charged engines with a system compensating ambient temperature and altitude.
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ⓘ This report gives advice only. It is not legal or type-approval advice.