Clean Gas Induction in Cars

For those that are interested in more fuel efficiency, as well as a reduction of pollutants into the air by your vehicles exhaust one alternative technology that is currently being used by vehicle manufacturers is clean gas induction.

Clean gas induction is also known as CGI and is a technology that is instrumental in the stratified charge engines. While clean gas induction has been used in diesel engines, it is currently most commonly found in engines that combust gasoline.

The term stratified charge engine comes from the unique type of cylinders these engines employ. In a typical gas engine (Otto Cycle Engine), fuel and air are mixed outside the cylinder and draw down into the cylinder during the normal intake stroke. On the other hand, stratified charge engines using clean gas induction use a direct injection system. Fuel injectors force fuel into one specific area on the cylinder called the sub-cylinder. The sub-cylinder is a small section on top of the main cylinder area. What results is a smoother, quicker charge that helps combust the fuel and air better- leaving very little fuel left.

Once the fuel is combusted the exhaust including very small amounts of fuel and air are cooled very quickly. This is an important point, because if the air cools quickly, it doesn’t have an opportunity to form NOx, which in a standard gasoline engine is one of the most dangerous pollutants an engine can create. Since stratified charge engines including clean gas induction do not give the exhaust an opportunity to create NOx, a catalytic converter is usually not necessary.

Advantages of Stratified Charge Engines with Clean Gas Induction

There are several advantages to using these types of engines, they include:

No Need for a Catalytic Converter- Catalytic converters are mandatory on most gasoline engines in the US because engines usually produce NOx- a dangerous pollutant which is made from oxygen and nitrogen that form after combustion. The main reason NOx forms is that the air which includes single atoms of nitrogen and oxygen are direct bi-products of combustion. In a normal gas engine, these two atoms stay very hot during the entire combustion process causing them to fuse together. In a stratified charge engine with clean air induction, both single atom oxygen and nitrogen cool quickly. Since these atoms can not form NOx, a catalytic converter is not needed.

Increase in Fuel Efficiency– Stratified charge engines are usually very fuel efficient compared to normal gasoline engines. Since they burn very clean and exhausts are minimized most vehicles with this type of engine can see gains of 4% to 20% in fuel efficiency.

Reduction of Emissions– As stated above, stratified charge engines with clean gas induction do not have the opportunity to create NOx as well as large amounts of other pollutants. These engines are seen as some of the greenest technologies available when it comes to gasoline combustion engines.

Disadvantages of Stratified Charge Engines Using Clean Gas Induction

While these engines are usually looked at favorably by engine enthusiasts and environmental groups, they do have disadvantages including price and engineering concerns.

High Price– many manufacturers are hesitant to introduce stratified charge engines due to the fact that they can be expensive, especially in research and development costs. While there are many manufactures that already create and sell CGI engines, they are not yet considered mainstream.

Engineering Concerns– While government fuel efficiency and pollution restrictions have become stricter in recent years; generally speaking most car manufactures have found technology work-arounds using the standard combustion engine. Since there are relatively few demands by the government to make gasoline engines even more fuel efficient or to reduce more pollutants- car manufactures will continue to take a wait and see approach if CGI technology will be needed.

Cars that Currently Use Clean Gas Induction

There are many vehicles that are using clean gas induction; however the technology hasn’t gone mainstream yet. Some manufactures that you will find specific cars with a clean gas induction component include; Audi, Mazda, Mitsubishi, Citroen, Peugeot and Volvo.