This is Part II of the comprehensive study of the North Atlantic (NAT) airspace. The main purpose of the research is to assess the potential savings of fuel consumption due to the proposed changes in the separation standards of the NAT airspace. The fuel savings estimates were obtained using 24 sample traffic days in 1996 and forecast traffic for the years 2000, 2005, and 2010. A forecast for the aircraft fleet changes in the NAT airspace was developed for this research and used in the fuel saving estimation for future years. The actual 1996 Organized Track System (OTS) was used for the simulation of all the non-RVSM (2000 ft vertical separation) scenarios. A modified OTS was developed for the reduced separation scenarios for each simulation day. We show that a 1000 ft vertical separation (RVSM) results in a fuel consumption saving ranging from 0.2% to 0.8% per year. Other significant results are also shown.