Propane is a clean-burning, efficient and reasonably inexpensive fuel. From boats and automobiles to gas-powered grills, people widely use propane in both commercial and consumer contexts. As gasoline prices have risen, automakers have also begun to explore using propane as an alternative fuel for cars, trucks and other vehicles. Although it has yet to go mainstream, propane does offer numerous benefits that gasoline doesn't, which could make it an excellent replacement.
Liquefied petroleum gas (LPG)Liquefied petroleum gases are a mixture of butane, methane and propane. A refinery separates the gases to make three different alternative fuels.
Overfilling prevention deviceAn overfill protection device, or overfilling prevention device, is a requirement on DOT propane containers with a capacity of 4 to 40 pounds. This device measures the amount of propane in the container and automatically stops the influx of propane when it reaches capacity. This is important, because propane liquid expands more than 14% as it converts to gas.
Clean-burningPropane is a clean-burning fuel source. This is because propane is insoluble in water. It's also non-toxic.
Prins VSIPrins VSI, or vapor sequential injection, is a popular conversion kit used to make gasoline engines run on propane. Part of the system's appeal is its ability to smoothly integrate with the existing engine, but it garnered praise for producing relatively low-emissions.
Octane ratingPropane has an octane rating of about 105, higher than that of premium-grade gasoline, which usually falls somewhere in the mid- to upper-90s. Fuels with high octane ratings are less likely to cause engine-knocking than those with low ratings, making them great for use in spark-ignited combustion engines.
Alternative Fuels and Advanced Vehicles Data Center has a detailed guide to propane that discusses its octane rating and applications as an alternative fuel.