Dedicated gaseous fuels have also been used to power internal combustion engines, but in very insignificant numbers due to numerous physical properties of the gaseous fuels. Namely, the low energy content that requires massive on-board storage, significant reduction in power, performance, and range; higher combustion temperatures that present problems for engine cooling and load handling and are sufficiently high enough to dissociate atmospheric nitrogen and form undesirable NOx emissions.

In conventional gasoline engines the liquid fuel is premixed with air in the carburetor, while in diesel and fuel-injection engines it is injected into the combustion chamber by a fuel pump and atomized, or turned into a fine spray, through an injection nozzle. Air flow into and out of the cylinder is controlled by valves. The atomized liquid fuel changes to a gaseous state, 'vaporization,' and it's molecules attach to oxygen molecules of air, 'volatilization.' Liquid fuels can not burn until they are volatilized. During the compression stroke the valves close and the containment of the cylinder is compressed. Due to the density and composition of gasoline, the compression causes a quantity of the vaporized and volatilized gasoline to return into a un-combustable liquid state.

In a gasoline engine, ignition of the air/fuel mixture is accomplished by a spark plug. In the diesel, combustion takes place automatically as soon as the fuel is injected. The volatilized fuel ignites and the force of the explosion drives the piston. This first explosion powers the vehicle. The release of heat from this first explosion vaporizes and volatilizes additional liquid fuel and reignites due to the auto-ignition temperature. Resulting in waves of combustions. The combustion wave explosions generate heat, that is sufficient to generate undesirable NOx emissions from the dissociated atmospheric nitrogen. The ambient air is typically composed of 20% oxygen required for combustion and 78% of nitrogen, N2, compounds.

The remaining un-burnt fuel (hydrocarbons) are released to the atmospheric as undesirable emissions or attempted to be burned-up in the catalytic converter. The emissions of hydrocarbons and NOx have caused severe damage to our environment, ozone layer, and the health and welfare of humans, plants, and animals. The engine efficiency of gasoline engines range from 25% to 30% and some diesels can achieve efficiencies up to 42%. This means that only a small percentage of the energy in the fuel is converted to mechanical power. The remainder goes, wasted into the atmosphere and as heat into the vehicle's cooling system.

Equipping of the Multi-Fuel System on a vehicle involves no modifications to the engine and / or to any fuel or emission systems. The Multi-Fuel System is comprised of two components:

A Fuel Reservoir to store the gaseous alternate fuel on-board the vehicle. Since the gaseous fuel is used simultaneously with the liquid fuel the capacity required to increase the vehicle range between refueling is small; as an example a typical passenger car only requires a Three (3) Gallon (propane) Fuel Reservoir. Since the fuel reservoir is so small there is little or no effect on the vehicle's cargo capacity and virtually no safety concern of additional fuel storage.

The Multi-Fuel System Controller is installed in the engine compartment. The Controller utilizes solid state electronic management to vaporize, treat, and control the gaseous fuel with triple redundant safety controls and without utilizing any external heat from the engine's cooling system or electrical heat to vaporize the gaseous fuel.

Treated and vaporized gaseous fuel is injected into the engine's intake manifold; homogeneously mixing with the engine's intake of atmospheric air. Liquid fuel is injected into the cylinder as it was before. Under the compression cycle, the air mixed with the gaseous fuel heats to hotter temperatures due to the alternate fuels higher 'heat of vaporization'. The increased temperatures during the compression causes the liquid fuel to stay in a gaseous state and forces more droplets of liquid fuel to vaporize and volatilize. Compression of the air/fuel mixtures never reaches autoignition, so pre-ignition is not a concern.

Ignition, as previously, is accomplished by a spark plug in a gasoline engine and automatically as diesel fuel is injected in a diesel engine. In addition to the increased vaporization and increase of pre-combustion temperatures; the gaseous fuels, due to their increased 'stoichometric flame speeds' of 0.43 of both LPG (propane) and natural gas vs. gasoline's 0.34, higher volatility, and higher autoignition temperature (high octane) causes a quicker and more spontaneous combustion; resulting in increased power without engine modification. The power increases,  in part, are due to the increase in volumetric efficiency from the requirement for less oxygen (air) in the air/fuel/alternate fuel mixture charge and maintains the engine's existing stoichometric ratios. Although the gaseous alternate fuel should increase the temperature of combustion of the fuel mixture over dedicated liquid fuel combustion, this has not been measurable and is believed to be negligible.

Since the liquid fuel is virtually vaporized and volatilized pre-combustion and since combustion is more rapid and complete there is one explosion, consuming the fuel and releasing its energy. No 'combustion wave'. This can be verified by a stethoscope and audible quieting of the diesel knock. Since there are no additional explosions of the combustion wave, excess heat is not generated, reducing the formation of NOx and the engine's cooling system is not strained dissipating the excess heat. Cooling system temperatures remain as before, because of thermostats, electronic cooling fans, etc.  but engine oil temperatures of 20 to 30 degrees Fahrenheit cooler can be measured with Multi-Fuel System operation. Exhaust with 'near-zero' hydrocarbons and NOx emissions is vented to the atmosphere. Since virtually no fuel is present in the exhaust gas there is no 'burn' in the catalytic converter. Exhaust temperatures of Multi-Fuel System operation are significantly reduced and a increased vapor content of the exhaust is observable and further indication of efficient combustion.

Additionally the properties of the gaseous fuels dissolve carbon and tar deposits from the combustion chamber after a period of operation. Combustion chamber deposits are responsible for significant increases in emission, heat generation, and inefficient combustion. Multi-Fuel System operation cleans the combustion chamber of even older high mileage vehicles and returns them to a clean efficient condition.

Fuel savings are generated since the combustion is more complete with less energy wasted to heat and to harmful emissions, less liquid fuel is required to maintain the same operation levels, yet torque is increased, providing more satisfactory engine performance, improved acceleration, and greater load hauling capabilities. In computer controlled engines, through the existing engine management sensors of RPM, speed, oxygen, etc. the amount of fuel delivered to the engine is automatically reduced, typically by adjustment of the fuel injector's pulse width cycle. This can be confirmed by electronically measuring the pulse width cycle of the fuel injectors. In carburetor and manual fuel injection engines a slight adjustment can be made to reduce liquid fuel to the engine. The Multi-Fuel System has been engineered so there is no need to adjust the engine's stoichmetric levels, timing, or spark advance. No engine, fuel,  or emission systems is modified, rendered ineffective, or substantially adjusted so there is no tampering of the engine, in conformance with the anti-tampering provisions of the Clean Air Act of 1990.

If in the event that the alternate fuel runs out, since it was not refueled, the operation of the vehicle, automatically returns to dedicated liquid fuel use without any control or adjustment required by the vehicle operator. Please note, that the power levels, low emissions, fuel economy, and engine temperatures return to previous levels. With the clean efficient combustion, cooler engine temperatures, elimination of tar and carbon combustion chamber deposits, and increased torque the engine longevity is substantially increased.