Since propane (also called liquefied petroleum gas or LPG) is now considered an alternative fuel under the Energy Policy Act of 1992, you might want to learn some more about propane vehicles, especially since there are an estimated 270,000 of them on the road in the United States (and an estimated 10 million worldwide). So what is a propane vehicle? In short, they are typically conversions from gasoline vehicles and fall into two types: dedicated propane vehicles which are designed to run only on propane, and bi-fuel propane vehicles which have two separate fuel systems to allow the vehicle to run on either propane or gasoline. The power, acceleration and cruising speed of the propane vehicle is similar to that of its gasoline-powered counterpart. Compared with vehicles fueled with conventional diesel and gasoline, propane vehicles can produce significantly lower amounts of harmful emissions.Unfortunately, no light-duty propane vehicles are currently available for sale as OEM from manufacturers and most vehicles on the road (with the exception of some medium and heavy duty vehicles) are a result of conversions handled by technicians who must receive licensing and approval for the EPA. The average cost of conversion for a car can range from 4,000 to 12,000, but these upfront costs are offset by decreased operating and maintenance costs over the lifetime of the vehicle not to mention the enormous upside to the environment regarding emissions.