Mr. Piccolo reminds the group that Mr. Radzimirski (Poland), in the GRPE January session and in subsequent documents circulated to the group, made two main remarks:

• ● As for R.115 proposed amendments, several retrofit system manufacturers find it difficult to meet the emission limit in R.115 because of a certain incapacity to correctly calibrate the engine on gas or, for example, on CNG because of the ineffectiveness of the catalyst. If the possibility to use petrol up to 20% in energy unit was accepted, it would be possible for such manufacturers to extend the operation with petrol in the gas mode after the cold start for some 200 – 250 seconds in a Type I test, in order to satisfy the requirements. As for petrol direct injection engines, that would not be possible since petrol use is mainly required in the second part of the cycle. Mr. Radzimirski proposes, therefore, to limit this provision only to vehicles with direct injection petrol engines.

• ● As for both proposed amendments to R.115 and R. 83, the proposed method for gas ratio calculation (Annex 6B) does not seem to be suitable for reference CNG fuel G25 that is composed of 86% mole of methane and 14% mole of nitrogen (average percentage). The measured CNG mass consumed during the cycle by fuel weighing (numerator of the gas energy ratio) would correspond to the total mass of methane and nitrogen, while the denominator would estimate only the equivalent mass of methane consumed during the cycle. In the case of G 25 reference gas, the calculated gas energy ratio would, therefore, be higher than the actual one. Therefore, the method for G25 needs correcting via, for example, a correction coefficient.

As for the first remark, Mr Piccolo stated that AEGPL shared the concern of Mr Radzimirski and, in principle, would keep the two regulations aligned. However, if the group agrees such a “decoupling” of the two proposals making R.115 more restrictive in comparison with R 83, AEGPL would not oppose it.

Regarding Mr Radzimirski’s second remark, AEGPL asks the group and, in particular, NGVA Europe to specify some correction factors to the gas energy ratio in the case of testing with G25.

Mr. Del Alamo (NGVA Europe) indicated that Fiat does not see the necessity of the amendment to R 83.

Mr. Tappe (CLEPA/Bosch) suggested to leave to the discretion of the OEM’s the opportunity to use the two fuels, gas and petrol, in the most synergistic way for any type of engine system, be it a PSI or GDI. This is in line with a request for more flexibility made by OEM suppliers. OEMs, to respect the CO2 obligations, are forced to minimize the use of petrol and have no reason to misuse of petrol to fulfil the emission limits in the gas mode. That said, due to some safety concerns about the gas mass measurement by weighing, Mr Tappe asked the group to evaluate a different method based on petrol and gas ECU’s data, validated by a proper initial comparison with the official results coming from the application of FC (carbon balance) formulae.

Mr. Castagnini (AEB) expressed concern that a change of this type would delay submitting the formal document. Hence, he suggests to add the new method proposed by CLEPA as an alternative.

My Rijnders, taking into account the positions of the members, proposed to convert the present R.83 proposal (GRPE-63-05-Rev.1) into a formal document for the next GRPE session with no modifications. As for the R.115 proposal, the formal document based on the informal GRPE-63-06-Rev.1 will reflect the comment received by the Polish expert, in restricting the scope of the provision related to the 80% minimum limit for gas energy ratio only to vehicles with petrol direct injection engines. In addition, Mr. Rijnders asked Mr Tappe to provide an appropriate text containing provisions for an alternative method to weighing the mass of gas. This could possibly be included in an informal document to be submitted to the June 2012 GRPE by GFV.

Furthermore, it is agreed that an adequate correction factor for G25 will be part of an informal document for the next GRPE session.

The group agrees and provide for a consistent revision of GRPE-63-06-Rev.1.