UN R168 Supplement 1 (00 series) · UNECE Regulation No. 168 (ECE R168) — Uniform Provisions Concerning the Approval of light duty passenger and commercial vehicles with regards to real driving emissions (RDE).
UN R168 — Supplement 1 to the 00 series of amendments
Base text → Supplement 1
- What changed
- Under paragraph 6.1., final RDE emissions are calculated for a 4-phase WLTC, and for vehicles with a diesel engine also for a 3-phase WLTC.
- The rules on single, dedicated and second RDE trips in paragraphs 9.3., 10.7.1. and 10.7.2. now apply only to vehicles with a diesel engine.
- At the manufacturer’s request and with approval of the approval authority, the permissible analyser drifts in Annex 4 may now be exceeded under two conditions. The difference between the uncorrected and corrected concentration values (Annex 7, paragraph 5.0.) must be lower than 6 per cent of the uncorrected values. The uncorrected and corrected emissions values must also give the same conclusion on an exceedance of the emissions limits.
- Why
- Japan applies RDE requirements based on 3-phase WLTC exclusively to vehicles with diesel engines. The proposal aims to clarify that only a 4-phase analysis is required for vehicles with a petrol engine.
- The proposal also corrects several incorrect references to paragraphs in the original version of the Regulation.
Q1What changed25 changes
3-phase WLTC evaluation for vehicles with a diesel engine (paras. 6.1., 9.3., 10.7.1. and 10.7.2.)
For vehicle types approved according to this Regulation, the final emissions at any possible RDE test must be calculated for evaluation with a 4-phase WLTC. For vehicles with a diesel engine, they must additionally be calculated with a 3-phase WLTC. Before, paragraph 6.1. named a 3-phase and a 4-phase WLTC for these vehicle types, without the diesel engine condition. The requirement for the 3-phase analysis, with the NOX limits of Table 1B, no longer starts with “For vehicles with a diesel engine”. Paragraphs 9.3., 10.7.1. and 10.7.2. on single, dedicated and second RDE trips now say “For vehicles with a diesel engine”.
3-phase evaluation “where applicable” (para. 9.2., Annex 8 para. 1., Annex 10 para. 4.3.3., Annex 11 para. 1.)
Several provisions now name the 3-phase WLTC or WLTP evaluation “where applicable”. In paragraph 9.2., “where applicable” now qualifies the 3-phase WLTC. In Annex 8, the 3-phase WLTC requirements for the Moving Averaging Window method now apply “where applicable”. The words “where applicable” also appear now in the altitude gain datasets of Annex 10 and in paragraph 1. of Annex 11. Before, these texts named the 3-phase evaluation without “where applicable”.
Paragraph references (paras. 6.4.1.2. and 6.4.1.3., Annex 11 para. 3.)
Paragraph 6.4.1.2. now refers to paragraph 6.4.3. instead of 6.4.2. for the technical criteria for selection of an additional vehicle. Paragraph 6.4.1.3. now refers to the tests of the vehicles required by paragraphs 6.4.3.2. and 6.4.3.6. instead of 6.4.2.2. and 6.4.2.6. In Annex 11, the RDE result evaluation factors use the functions of paragraph 3.1. for vehicles with ICE and NOVC-HEV and paragraph 3.2. for OVC-HEV. Before, these references were paragraphs 2.2. and 2.3.
Example of an approval number (paras. 5.2.1. and 5.2.2.)
In the explanation for Section 2, the words “of this UN Regulation,” no longer have square brackets. The example approval number is now “E11*168R01/02*0123*01” instead of “E11*[168]R01/00/02*0123*01”. Its explanation now says that the extension was issued “to Supplement 2 to Series of Amendments 01”. The words “which is a Level 2 Approval” are removed.
Approval mark in Annex 3
Annex 3 no longer says that, in the approval mark, the type approval number must be accompanied by an alphanumeric character reflecting the approval level. The first graphic in Annex 3 is amended. A new paragraph after the second graphic of Annex 3 explains the example mark. It says that the example mark shows approval in the United Kingdom (E 11) under approval number 2439.
Exceeding the permissible analyser drifts (Annex 4, para. 6.1.)
At the request of the manufacturer and with approval of the approval authority, the permissible drifts may now be exceeded if two conditions are met. The first condition concerns the difference between the uncorrected and the corrected concentration values according to paragraph 5.0. of Annex 7. This difference must be lower than 6 per cent of the uncorrected concentration values. Second, the uncorrected and the corrected emissions values must give the same conclusion on whether there is an exceedance of the emissions limits.
Q2Why it changed
- Proposed by
- Experts from the International Organization of Motor Vehicle Manufacturers; expert of Japan (Annex 4 analyser drift)
- Working party
- GRPE, 91st session (October 2024)
Reasons
Japan applies RDE requirements based on 3-phase WLTC exclusively to vehicles with diesel engines. Some text of the original version can be interpreted as requiring fundamentally a 3-phase analysis of the test data. The limits for this analysis apply only to vehicles with a diesel engine. The proposal aims to remove this interpretation and clarify that only a 4-phase analysis is required for vehicles with a petrol engine.
Sources (3)
“Japan applies RDE requirements based on 3-phase WLTC exclusively to vehicles with diesel engines.”
“some text can be interpreted as requiring fundamentally a 3-phase analysis of the test data despite limits for this analysis only being applied to vehicles with a diesel engine.”
“This proposal aims to remove this interpretation and clarify that only a 4-phase analysis is required for vehicles with a petrol engine.”
Several incorrect references to paragraphs were identified in the original version of the Regulation. The proposal corrects them.
Source
“several incorrect references to paragraphs have been identified in the original version of the Regulation and corrections are proposed.”
Proposer's reason (informal document GRPE-91-15-Rev.1)
UN Regulation No. 168 does not contain any differentiation with regards to Levels. For this reason, the reference to “Level 2 Approvals” is removed from the example of the approval number in 5.2.2. The first paragraph of Annex 3 is removed. It refers to an alphanumeric character indicating the level of the approval that is not present within UN Regulation No. 168.
Submitted by Experts from OICA. Working party adoption: ECE/TRANS/WP.29/GRPE/91, para. 30.
Sources (2)
“Removal of the reference to “Level 2 Approvals” within the example of the approval number given in 5.2.2. of UN Regulation No. 168 as this UN Regulation does not contain any differentiation with regards to Levels.”
“it is referring to an alphanumeric character indicating the level of the approval that is not present within UN Regulation No. 168.”
Proposer's reason (informal document GRPE-91-15-Rev.1)
In the first graphic of Annex 3, two markings of distances (“a/2” and “a/3”) were not readable. The proposal corrects the graphic to include these markings. An explanation is added to the example of the approval mark, as it is present within other UN Regulations.
Submitted by Experts from OICA. Working party adoption: ECE/TRANS/WP.29/GRPE/91, para. 30.
Sources (2)
“Within the first graphic of Annex 3 two markings of distances (“a/2” and “a/3”) are not readable in its current form. Correction to include these markings.”
“Addition of an explanation to the example of the approval mark as it is present within other UN Regulations.”
Proposer's reason (informal document GRPE-91-09-Rev.1)
In Japan, the responsible authority and vehicle manufacturers encounter invalid and repeated RDE tests when the PEMS concentration drift is out of criteria. This happens even though the NOx emission results are expected to be lower than the emission limit. Annex 8, Appendix 1 of UN Regulation No. 49 permits a choice: an invalid test or a correction for the concentration drift. This applies when the zero and span drift is higher than permitted. The proposal aims to clarify and align the provision of PEMS concentration and emission correction with UN Regulations as a common provision. The amendment is expected to avoid unnecessary RDE test repeats and extra burden for responsible authorities and vehicle manufacturers.
Submitted by Expert of Japan. Working party adoption: ECE/TRANS/WP.29/GRPE/91, para. 30.
Sources (4)
“In Japan, the responsible authority and vehicle manufacturers are encountering the RDE test invalid and test repeated when PEMS concentration drift is out of criteria even though the NOx emission results are expected to be”
“Annex 8, Appendix 1 in UN Regulation No.49 permit to select the test invalid or corrected per the concentration drift if the difference between the pre-test and post-test results for the zero and span drift is higher than permitted.”
“The proposal aims to clarify and align the provision of PEMS concentration and emission correction with UN Regulations as common provision.”
“This amendment is expected to avoid the unnecessary RDE test repeat and extra burden for responsible authorities and vehicle manufacturers.”
Document trail
- 2024-07ProposalECE/TRANS/WP.29/GRPE/2024/20Proposal by the experts from the International Organization of Motor Vehicle Manufacturers
- —RevisedGRPE-91-09-Rev.1Proposal by the expert of Japan on the analyser drift in Annex 4
- —RevisedGRPE-91-15-Rev.1Proposal by the experts from OICA to amend GRPE/2024/20
- —Working party adoptsECE/TRANS/WP.29/GRPE/91GRPE session report, para. 30
- 2024-12Sent to WP.29ECE/TRANS/WP.29/2025/29Text that GRPE sent to WP.29 and AC.1
- 2025-03WP.29 adoptsECE/TRANS/WP.29/1184Adopted at the 195th session (session report, para. 109)
- 2025-09-26In forceC.N.538.2025.TREATIES-XI.B.16.168UN depositary notification
Q3Who is affected
Vehicle manufacturer
- Consider requesting approval to exceed the permissible drifts if conditions (i) and (ii) in Annex 4 are met.
Component supplier
- No direct action for this role.
Technical service / Approval authority
- Be ready for manufacturer requests to exceed the permissible drifts under conditions (i) and (ii) in Annex 4.
See every change side by side
RegVault customers compare every version of UN regulations, read the consolidated text and download the PDF.
ⓘ This report gives advice only. It is not legal or type-approval advice.