However the benefits of hydrogen injection can be taken advantage of by manipulating the operating parameters of the engine. A petrol engine produces the greatest torque with a stoichio-metric air/fuel mixture, but can be much more efficient when run with an ultra-lean mixture, especially at cruise throttle settings for the following reasons:

The ultra-lean mixture opens the throttle further and reduces the vacuum in the engine manifold that causes the engine to use up horsepower to suck the combustion air into the combustion chamber. The ultra-lean mixture reduces the horsepower used in sucking in the air. Running an ordinary engine with an ultra-lean air/fuel mixture is the job of the Hydrogen Oxygen Generation System (HOGS). Everything possible must be done to prepare the mixture to combust.
The fuel heater heats the petrol to the highest possible temperature without causing vapour problems within the fuel injection system, so that when the hot fuel is injected, more of it will vaporise. The fuel vaporising system vaporises more fuel that is brought to the engine through the evaporative emissions control system. This combination vaporises as much fuel as possible to prepare it for combustion (liquid fuel does not combust until it is vaporised).

The hydrogen injection accelerates ignition of the vaporised fuel at the moment the spark plug fires. This forces the ultra-lean air/fuel mixture to ignite when normally this lean of a mixture would simply misfire.

To create the desired ultra-lean air/fuel mixture in a fuel injected engine the electronic control circuit of the HOGS does two things:
It “cuts the stoichio-metric guard” by disconnecting the oxygen sensor which is in place to prevent a stoichio-metric  mixture (no excess oxygen or fuel) going out the exhaust.

It also modifies the signal from the Mass Air Flow or Manifold Absolute Pressure sensor going to the ECU (engine control unit) or PCM (power control module) thereby telling the engine computer that less air is present than there really is. This causes the computer to 'demand' less fuel to be injected into the engine and therefore guarantees a leaner mixture. The mixture is usually set at the leanest mixture that enables a smooth power output.
This ultra-lean mixture also keeps the combustion temperature down to a point where Nitrogen Oxides emissions are avoided. The permanent engine treatment component of the HOGS reduces friction and drag inside the engine, which further increases the engine’s efficiency.

At idle and low cruise power settings the benefits of a HOGS are minimal because there is little fuel being combusted.

The Nature of Hydrogen 

1. Hydrogen is the simplest, lightest element in the universe. It is made up of a one proton and one electron.
2. Hydrogen being 14 lighter than air, when Hydrogen Fuel is released into the atmosphere, it dissipates immediately upward, making it very safe.
3. Hydrogen is the most abundant element in the universe, making up more than 90% of all matter. On Earth, it is the third most abundant element in the Earth's surface.
4. In its normal gaseous state, hydrogen is colourless, odourless, tasteless, and it is non-toxic.

The Hydrogen Burning Process

Hydrogen burns readily in presence of oxygen, releasing considerable energy as heat and producing only water as 'waste'.

When hydrogen burns in air (which is mostly nitrogen), some oxides of nitrogen (NOx) can be formed, but much fewer pollutants are formed than when normal hydrocarbon fuels such as petrol and diesel fuel are burned. Because no carbon is involved, using hydrogen fuel does not contribute to Global Warming.

Hydrogen Gas has a much higher flashpoint than petrol. The self-ignition temperature of hydrogen is 550 degrees Celsius. Fuel can ignite from 280 degrees onwards, pending the grade.

When ignited, hydrogen burns upward, and is quickly consumed.  Liquids and Vapours such as petrol fuel and diesel vapours remain a threat for much longer.

Hydrogen is non-toxic. Hydrogen is a naturally-occurring element in our atmosphere while all petroleum fuels are poisonous to humans and animals.

Hydrogen combustion produces only water. When hydrogen is burned in oxygen, only pure water H₂0 is produced. In any case, when a hydrogen engine burns, it actually cleans the surrounding air, by completing combustion of the unburned hydrocarbons that surround us. Compared with the toxic compounds (carbon monoxide, nitrogen oxides, and hydrogen sulfide) produced by petroleum fuels, the products of hydrogen burning are much safer.

Hydrogen makes an excellent fuel because it works well as an energy carrier. By the way, it has been used in the Space Industry for the last 60 years.

So what exactly is a supplemental HOGS?

Hydrogen Oxygen Generations Systems are known as Supplemental Hydrogen generators. A supplemental hydrogen generator is basically a tank that holds distilled water and an electrolyte, such as potassium hydroxide. The distilled water is charged to induce electrolysis, which separates the hydrogen and oxygen molecules. The hydrogen and oxygen that has been released is then collected and forced into the engine through the air intake system. The added oxygen increases the octane level of the fuel. Once the supplemental hydrogen is added to the fuel mixture of the engine, it helps increase the flame spread during the combustion process, and thus makes the burning process faster and cleaner.

This way more of the fuel is burned, more power generated, and less waste is produced after the Intake-Combustion-Ignite cycle has take place.