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Gasoline Direct Injection

The advancement in Gasoline Direct Injection is perhaps the most important development in the field of fuel injection in the last decade. You can get better car insurance quotes with these engines. In conventional engines, multi-point injection technology is used, where the fuel is injected through the intake port of each cylinder. This technology was a significant improvement over traditional mechanical carburetion system in terms of the efficiency and response but it was far from the best possible solution because fuel mixes with air before entering the cylinder.

Keeping this in mind, a new method of injecting fuel was devised. In this technique, the gasoline is highly pressurised and injected via a common rail (high pressure pipe) fuel line into the cylinder itself. This way, the fuel burns more efficiently and we get high efficiency and better response from the engine since there is lesser amount of uncombusted fuel after a stroke is over.

The working of a direct injection engine is as follows. A mixture of gasoline and air is taken into a cylinder, compressed with the help of a piston and finally ignited with a spark from the spark plug. The air and fuel is not mixed outside the cylinder but rather in the cylinder itself.

The possible benefits are as follows:

- Higher fuel efficiency: Due to the fact that the mixture of fuel and air takes place in the cylinder itself instead of a separate chamber, there is less wastage of fuel. More quantity of fuel is used in combustion and less fuel goes waste. This leads to more miles per gallon.

- Greater power: This is evident by the fact that fuel mixture gets more evenly dispersed results in greater response from the engine and hence more power. Before the advancements in the technology as such, diesel had the advantage of giving more powerful torque for dynamic acceleration at lower revolutions. Now even petrol engines provide the same as diesel.

- Greater control over Emission Levels: This is because with a GDI system in place we are in total control of the amount of fuel entering the cylinder as well as the injection timings. Here the EMS (Engine Management System) regulates the fuel injection and timing according to the conditions. Eg. if the vehicle is being used for light running conditions with little or no acceleration, the fuel is injected at a later stage of compression. But if there are heavy loads(steep ascent) and rapid acceleration then fuel is injected during the intake stroke and homogenous mixture is used. Generally , direct injection is accompanied by other engine technologies such as turbocharging to provide the required power and efficiency.

- Two-wheelers: Normally a large portion of the fuel-air mixture entering goes out unburned when the exhaust port opens but with DI, the fuel is not injected till the exhaust port closes. This increases the amount of fuel that actually burns, hence increasing fuel economy.

Thus, we have seen that Gasoline Direct Injection allows greater precision and control with the best fuel economy possible. Almost all the top carmakers in the world have been working and are producing vehicles which have implemented GDI technology. Be it Audi, BMW or DaimlerChrysler, everyone has invested huge amounts of money and resources to deliver engines that make the best use of GDI technology.