What is better port injection or direct injection?

Port injection provides a better, more stable air/fuel mixture at lower engine speeds, which results in smoother operation upon startup. At higher rpm, direct injection provides a greater cooling effect, allowing for more power and less chance of knock.

What is the difference between GDI and PFI?

In a GDi engine fuel is also injected at higher pressures so fuel droplet sizes are smaller. Injection pressures are in excess of 100 bar compared to a PFI injection pressure of 3 to 5 bar. Fuel droplet size with GDi are <20μm compared to a PFI droplet size of 120 to 200μm.

Why new cars are using both direct and port fuel injection?

Lots of new car engines these days are built with both port and direct fuel injection. Port injection is used at low RPM for better air-fuel mixing, which results in a more stable, efficient combustion. Direct injection, on the other hand, cools the air inside the cylinder, greatly reducing the probability of knock.

What are the differences between carburetors port injection and direct injection?

In carbureted systems the fuel gets drawn from the tank, while in a Fuel Injected system it depends on a fuel pump installed inside the tank for a fine-grained control over fuel flow. The fuel injection nozzle also goes directly inside the combustion chamber.

Which cars have direct and port injections?

Examples include:

• Redesigned Ford 3.5L EcoBoost and V6 engines.
• Lexus 2GR-FSE engines.
• Audi’s VW Group 3.0-liter V-6 and 5.2-liter V-10 engines.
• Toyota’s 2.0-liter in-line four-cylinder engines built by Subaru, and D4-S 3.5-liter V6 and 5.0-liter V-8 engines.

What is PFI fuel injection?

Port Fuel Injection vs. Gasoline Direct Injection Historically, the most widely produced internal combustion engines were of the Port Fuel Injected (PFI) design, where the fuel is sprayed into the intake ports to mix with incoming air. In fact, many new vehicles are still manufactured with this engine design.

What are the advantages of a direct fuel injection?

Fuel Direct Injection (GDI) engines presents various benefits, It avoids fuel wall film within the manifold, improves accuracy of air/fuel ratio in the course of dynamics, reduces throttling losses of the gas exchange with the aid of stratified and homogeneous lean operation, higher thermal effectivity by means of …

Which is more fuel efficient carburetor or fuel injection?

A fuel injection system precisely delivers fuel in the right amount and can tweak it according to several parameters resulting is less fuel wastage and better fuel efficiency. A carburettor is unable to adjust the fuel ratio according to the engine conditions.

What is the disadvantage of direct fuel injection?

The big disadvantage of direct injection is carbon buildup on the backside of the intake valves. This can throw a computer code, and could result with an engine miss or a ignition failure. The other disadvantage of direct injection is cost.

What is the difference between direct and indirect injection?

The main difference between Direct and Indirect Injection is the layout of the injection system, the Indirect Injection System actually has a small swirl chamber above the cylinder, where the fuel is injected, this chamber also contains the glow plug, which is much needed to start the engine, the Direct Injection.

Is indirect injection more fuel efficient?

Fuel efficiency is lower than with direct injection because of heat loss due to large exposed areas and pressure loss due to air motion through the throats. This is somewhat offset due to indirect injection having a much higher compression ratio and typically having no emissions equipment.

What are the problems with direct injection?

Another problem with direct injection is with ethanol fuel. Ethanol is known to speed up the corrosion rate of some metals that are used in an engine. With the higher pressure of a direct injection engine, and thanks to the fuel injector being exposed to in-cylinder explosions, there’s a higher chance of a problem or failure.