Turbocharged fuel stratified injection (TFSI) denotes a type of forced-aspiration ("turbo") engine where the fuel is pressure-injected straight into the combustion chamber in such a way as to create a stratified charge. FSI (VAG) direct injection technology increases the torque and power of spark-ignition engines, makes them as much as 15 percent more economical and reduces exhaust emissions.
Contents
Advantages
Some advantages of TFSI engines:
- Better fuel distribution and better fuel charge inside the combustion chamber
- During the injection process the fuel gets evaporated, cooling the cylinder chamber
- Higher compression ratios, which translates into more power
- Increased fuel combustion efficiency
- Higher power during pick-up of vehicle.
Disadvantages
- Huge rise of number of emitted exhaust particles
- Carbon build up behind the intake valves. Since fuel is directly injected inside the combustion chamber, it never gets a chance to wash any contaminants behind the valves. This results in excessive carbon build up over time, hindering performance. Some cars (like the Toyota 2GR-FSE engine in the Lexus IS) combine direct injection with traditional multi port fuel injection to ameliorate this problem.
- More expensive - much higher pressure fuel pumps are required to inject the fuel directly into the cylinder. This requires fuel pressures of up to 200 bar, much greater than a traditional multiport injection setup. See direct injection.
References
Turbo fuel stratified injection Wikipedia(Text) CC BY-SA