Suggestions on revising national standard GB 18047 (2)——Concurrently discuss new edition of ISO 15403

According to new edition of ISO 15403 and ISO/TR 15403 published in 2006, a series of suggestions for revising enforced national standard Compressed natural gas as vehicle fuel(GB18047) are put forward in this article: (1) the content about purpose and target of GB18047 should simply be clarified in chapter 1 (scope); (2) the index of water dew point should be revised to that of water content; (3) the index of gross caloric value should be cancelled; (4) the expression of Wobbe index in paragraph 5.6 should be revised and renamed to Wobbe index limits, the content of Appendix B should be re-writed; (5) Appendix A should be re-writed, the antiknock properties, AVL method for calculating methane number (MN), EN 589 method for calculating octane number and so on should be added.