16. Some key issues are explained about the HDDF regulations: the D-F retrofit regulation is for type approval of ‘systems’ while R.49 is for type approval of engines; some tension exists between OEMs and retrofitters;

17. Principles of HDDF need some explanation: Type approval process; retrofit system family; emission tests: Engine test and simplified test; methane emissions; and safety.

18. Type approval will require UNECE retrofit system regulations but national requirements also must be considered.

19. Application range: means a group of engines to which the retrofit system is approved to be applied. The initial range of the retrofit system is the R49 engine family of the demonstration engine.

20. Actual applications: means type approved or notified retrofit systems (fulfilling all emission and other requirements).

21. Question: What happens when a manufacturer wants to add something to the system? This would be possible under national regulations if allowable.

22. Emissions Tests: Type Approval Extension: PEMS (portable emissions measurement system) could be used. A back-to-back comparison between a test in the diesel mode and a test in the dual-fuel mode is required. But the details of the simplified method still have to be developed and verified.

23. Methane emissions: This is an on-going, difficult issue for CNG/LNG dual-fuel retrofit systems. The challenge is to maintain the environmental performance of the retrofit without compromise on greenhouse gases or general pollution. In creating a good balance for retrofitters it also is important not to create an R49 “bypass” based on different emission limit values. Two options have been discussed: 1) Possibility to claim CO2 reduction: All emission limits for dual-fuel mode as specified in the applicable R49 series of amendments apply; or 2) The applicable R49 series of amendments apply for NOX , NMHC, PM and CO emission limits for dual-fuel mode as specified in the regulation. The CH4 emissions shall not exceed the following gas energy ratio (GER) dependent CH4 limit: CH4 ≤ 6.84 ∗ GER/100 AND CH4 ≤ 6 [g/kWh]. It should be discussed whether to amend the 05 series of amendments to R49 to align the CH4 emission requirements for OEMs and retrofit system.

24. Question: Has an equal relationship been proposed between ETC and PEMS? Mr. Dekker suggested that there is no correlation between a retrofit and the original PEMS test. A back-to-back emissions test on the road was done (the TNO method). Then the test before and after the conversion should have similar results. But this is not a verified test procedure and much more data would be required. If anyone has such test data please help the HDDF TF.

25. Question: What sort of methane emissions levels are anticipated? It depends on the GER and replacement of the diesel. Retrofits might be anticipated to be zero-to-10% CO2 reduction over the full diesel mode. (This is a ‘best estimate’.)

26. Safety: OICA raised concerns regarding possible torque differences between diesel and dual-fuel operation (physical and/or CAN parameters). A possible solution (torque test) is in development

27. Question/clarification: Greater explanation is asked about safety and torque. There might not be a match between the real and indicated torque. There could be a safety issue if this would result in the calculation of incorrect payload information for brake assist, stability control for ABS systems.

28. Next steps and time schedule: GFV has the following targets in order to complete the HDDF regulation: 1) An informal document enabling type approval of Engine Retrofit Systems will be submitted to the next GRPE (January 2016); 2) An informal document enabling type approval of Complete Retrofit Systems will be submitted to the June 2016 GRPE; and 3) A formal document for the complete regulation will be submitted for the January 2017 GRPE.

29. Mr. Rijnders summarized that the HDDF TF work has been challenging and putting these complex issues into a comprehensive regulation is taking time. On the other hand, the HDDF understands that forward motion is required. But a balance must be achieved between good basic regulation and serving the needs of the HDDF retrofit system manufacturers and suppliers. The regulation must be robust and sensible. Unfortunately we don’t have a draft regulation at this time, however, the HDDF TF stakeholders are working hard on drafting even as some fundamental discussions on specific issues are being finalized. Regular weekly/monthly drafting meetings (teleconferences) are on- going so that the regulation can be drafted in a timely fashion.