Fuel oil pollution control and additional maintenance required after burning it often outweigh the low cost of the fuel. Burning fuel oil, particularly residual fuel oil, produces uniformly higher carbon dioxide emissions than natural gas. Heavy fuel oils continue to be used in the boiler "lighting up" facility in many coal-fired power plants. This use is approximately analogous to using kindling to start a fire. Without performing this act it is difficult to begin the large-scale combustion process. The chief drawback to residual fuel oil is its high initial viscosity, particularly in the case of No. 6 oil, which requires a correctly
Ethanol fuel by country The first flex motorcycle was launched to the market by Honda in March 2009, and a second model in September 2009. By the end of 2009, both Honda flexible-fuel motorcycles had sold a total of 183,375 units, representing an 11.4% market share of the Brazilian new motorcycle sales in that year. Two other flex-fuel motorcycles manufactured by Honda were launched in October 2010 and January 2011. During 2011 a total of 956,117 flex-fuel motorcycles were produced, raising its market share to 56.7%. Cumulative production of the four available flex fuel models since 2009 reached 1.48 million units in December 2011.