If the country wants to minimize the reception of comments in this part of the inventory during the technical review, it is recommended to follow the guidance established in the 2006 IPCC Guidelines (Volume 2 Energy, Chapter 3: Mobile Combustion, Section 3.2.1.3) which refers to the topic consulted in the question and check the use of corresponding decision trees in Chapter 3. According to the 2006 IPCC Guidelines, “If the distribution of fuel use by vehicle and fuel type is unknown, it may be estimated from the number of vehicles by type. If the number of vehicles by vehicle and fuel type is not known, it may be estimated from national statistics”. Please also take into account that if the CH4 and/or N2O for mobile road are Key categories, it is good practice to obtain more information on parameters that influence emission factors. The guidelines also indicate that if the combustion is complete, the amount of CO2 is nearly the same irrespective of the combustion engine, but N2O and CH4 may differ, so in terms of CO2 it is not expected a large over or underestimation. If the country still cannot differentiate among subcategories as in the examples provided (1.A.3.b, 1.A.4), with a gross simplification may assume that all the fuel is consumed by the sector with a presumptive higher consumption and the other smaller consumptions are considered as “IE” : for example that “Gasoline” is consumed only by Cars and use the Notation Key “IE” for all the other types of vehicles using the same fuel. The same for “Heavy Duty trucks and Buses” in the case of “Diesel oil”, and so on, and include an explanation in the NID and a commentary in the Documentation Box at the bottom of this table. The same for subsectors of Sector 1.A.4 included in the question. However, expect to receive comments from the review team during the technical review for this super simplification.