Understanding Alternative Fuel Conversions

Once again, fuel prices are on the rise along with consumer interest in alternative ways of fueling their vehicles. Many people are unable to purchase a new vehicle that is designed to operate on alternative fuels. So does this leave them out of the "green" trend in automotive technology or allow them to potentially reduce their pain at the pump? For years there have been conversion companies that offer systems to allow original equipment manufacturer (OEM) vehicles to operate on alternative fuels. One of the main concerns is whether or not these conversions are reliable. If we take a look at the required certifications, agencies, and what a conversion actually is, we will be able to determine that a properly-converted vehicle can be as reliable as an OEM vehicle.

A converted vehicle is a vehicle that was originally designed to run on gasoline or diesel fuel and has been altered to operate on an alternative such as natural gas or propane. The conversions differ with each application and their intended use. A conversion may be dedicated, bi-fuel, or dual-fuel. Let's take a look at the differences in these conversion systems as these terms are often misused and misunderstood.

A "dedicated" system is one that is installed on an OEM vehicle where the gasoline system is removed and can only operate on the alternative fuel. This conversion is usually purchased by fleets that have a central base with a filling station on property. A dedicated system has benefits that are not able to be accomplished with other conversions due to the characteristics of the fuels. Both natural gas and propane have higher octane ratings than gasoline or diesel; by designing the system to operate on one fuel only, we are able to accomplish better fuel economy with less tailpipe emissions. The downfall to a dedicated system is the ability to conveniently fill up at any fueling station and the range is limited to the amount of fuel storage. The fuel storage systems can be heavy and consume storage space of the vehicle.

The inconvenience of range and fueling can be reduced by installing a "bi-fuel" system on the vehicle. A bi-fuel system is one in which an OEM vehicle is converted by installing an alternative fuel system and keeping the existing gasoline system. The systems work independently of each other; this allows the operator to choose which fuel the vehicle is operating on by simply activating a switch mounted inside the vehicle. For example, if the operator is running on propane and runs out of fuel, the system will automatically switch to gasoline. This operation does not work in reverse; if you run out of gasoline the vehicle will shut down just as a normal vehicle would; you then have the ability to manually switch to propane. Bi-fuel vehicles do not work with normal diesel engines because they use compression ignition while gaseous fuels (natural gas and propane) use spark (two stroke international) ignition.

The newest type of conversion is the dual-fuel system. A dual-fuel vehicle is one that has the ability to supply two fuels into the combustion chamber at the same time. This is possible in two different methods. The first type will have two sets of injectors introducing different fuels to the engine from separate tanks. A good example would be a diesel engine that uses a small amount of diesel to ignite under compression that in turn ignites a gaseous fuel that will not ignite under compression alone. The second type of dual-fuel system is one that is able to operate on two different fuels that are stored in the same tank. These dual-fuel vehicles are available from most automotive manufacturers and are known as flexible fuel vehicles. Flexible fuel vehicles operate on gasoline, E85, or any combination of the two fuels in the tank. Just recently the Environmental Protection Agency (EPA) approved the first-ever ethanol conversion system for aftermarket installation.

The EPA approves conversion systems by model year, vehicle model, and engine family according to Mobile Source Enforcement Memorandum 1A (Memo 1A). The Memo 1A was issued in 1974, amended in 1997, and revised in 1998. The original purpose of Memo 1A was to enforce the tampering prohibitions of the Clean Air Act with respect to maintenance and use of aftermarket parts. The revisions allowed vehicles to be converted to alternative fuels while still complying with the Clean Air Act's tampering prohibitions and ensuring that emissions are not degraded through the conversion process.

In the mid 1990s, conversion systems were found to be producing worse emissions than original baseline emission readings. This preempted the revisions in 1997 to require more stringent testing of alternative fuel vehicle conversions. The conversion systems of today are very reliable and efficient due to the stringent policies of the EPA. These systems do not void factory warranty and sometimes come with an additional warranty that covers the conversion system.

The EPA refers to a vehicle converter as a small volume manufacturer who holds a Certificate of Conformity which ensures the conversion designer, producer, or manufacturer of the equipment and the installation companies produce and/or install aftermarket components that are safe, durable, and meet the emission standards of the original model year of the vehicle. Any individual wishing to convert a vehicle to operate on alternative fuels must go through a company or organization associated with a certificate holder, and the work must be completed by a licensed technician associated with that company.

As a word of caution, unfortunately not all companies offer conversion systems that meet EPA requirements. If you are considering the option of converting your vehicle to operate on an alternative fuel, please do your homework and ensure the conversion system meets EPA standards. More information about EPA regulations and conversions can be found at the U.S. Department of Energy's Web site or at the EPA's Web site.

Converted vehicles are just one more way for us to help in reducing our dependence on foreign oil and help reduce greenhouse gases!