Just to clarify, the "T" is to denote the TFSI technology which reduces emissions, increases power and fuel economy.
3.0 litre V6 TFSI
The FSI part is very clever and combined with forced induction it creates Turbo fuel stratified injection (TFSI). Its very clever hence why Audi feel they need to highlight it in the badge. Its avail on a few of the powertrains and the FSI part is famous for being on the B7 RS4 4.2 taking the old 4.2 v8 from the B6 S4 and adding an extra 74 BHP (340 to 414 or 344ps to 420ps, pet hate when ps figures are quted as bhp figures - 1bhp = 0.987ps) and increased fuel economy, although its not just the FSI part and is helped by other modifications and technologies. Just FSI is said to increase power by as much as 15 percent.
Instead of trying to explain it further, here is the Wiki info:
Turbo 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.
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.
So basically the T is is part of the overall induction technology title, not specific to turbo's or superchargers.
For me, the OEM badge is the correct one, but the supercharged badges do look good.
I'll see how I feel when I get mine, currently stills searching (5 months so far) for the right B7 RS4 but beginning to think the right choice would be a B8 S4 to replace the B6 S4.
Sorry for the long winded write up, had to do it.
