So THAT'S what FSI stands for

[MotherTucker]

I have had a lot of people look at the engine bay and ask "What is FSI?" because it says it on the engine. It was kind of embarrassing to answer "I don't know". So I looked around a bit, and found it stands for Fuel Straight Injection.

{UPDATE} We've had a few responses below that claim it stands for Fuel Stratified Injection. It would be good to get Audi's official word on this. {/UPDATE}

It means the fuel is injected directly into the cylinder, instead of into the intake manifold like most fuel injected gasoline cars. It's a bit more efficient but is tricky to get the air and fuel mixed, evidently. So Straight or Stratified, that's what it's about.

Here's a link to a somewhat dated but very good technical article on it:

http://www.canadiandriver.com/articles/jk/051116.htm


And here's a link to an article on the new Audi V10 FSI engine:

http://www.autoblog.com/2007/11/17/l...ine-on-display

Now I know!

mt

[vjma]

I thought it stands for "Fuel Stratified Injection" instead....

http://germancarwiki.com/doku.php/fsi

[wedouglas]

I'm pretty sure that this is the direct injection technology that is making its way through the industry. Just a different name.

[650Berg]

The "S" in FSI does in fact stand for "Stratified" and not "straight".

FSI = Fuel Stratified Injesction, as mentioned earlier.

[650Berg]

I think you will find that in all Audi/VW training literature it does in fact stand for "Stratified" . I should hope I know what it stands for, after all I do work for the company.........and am an R8 tech. Hope that helps