because both are forms of natural gas. Advantages over gasoline and diesel LNG – and especially CNG – tends to corrode and wear the parts of an engine less rapidly than gasoline. Thus it is quite common to find diesel-engine NGVs with high mileages (over ). CNG also emits 20-29% less than diesel and gasoline. Emissions are cleaner, with lower emissions of carbon and lower particulate emissions per equivalent distance traveled. There is generally less wasted fuel. However, the cost (monetary, environmental, pre-existing infrastructure) of distribution, compression, and cooling must be taken into account. In addition, natural gas has a higher Octane rating than gasoline, with an octane rating of 112 RON/105 AKI for propane and 120 RON/120 AKI for methane, making it less likely to cause engine knocking. Inherent advantages/disadvantages between autogas (LPG) power and NGV Autogas, also known as LPG or propane, has a different chemical composition. However, it is still a petroleum-based gas produced from refining petroleum oil and has several inherent advantages and disadvantages, as well as noninherent ones. The inherent advantage of autogas over CNG is that it requires far less compression (20% of CNG cost), is denser and easier to store as at this lower pressure it is a liquid at room temperature, and thus requires far cheaper tanks (consumer) and fuel compressors (provider) than CNG. As compared to LNG, it requires no chilling (and thus less energy) or problems associated with the extreme cold such as frostbite. Like NGVs, it also has advantages over gasoline and diesel in terms of cleaner emissions and less wear on engines than gasoline. A major drawback of LPG is its safety. The fuel is volatile and flammable, and the fumes are heavier than air, which causes them to collect in a low spot in the event of a leak, making it far more hazardous to use. More care is needed in handling. Besides this, LPG (40% from Crude Oil refining) has historically been more expensive than Natural Gas, even though the energy density per weight is higher. Current advantages of LPG power over NGV In places like the US, Thailand, and India, there are five to ten times more LPG stations, thus making the fuel more accessible than NGV stations. In some countries like Poland, South Korea, and Turkey, LPG stations and autos are widespread, while NGVs are not. In addition, retail LPG fuel is considerably cheaper