[928S]

Originally Posted by yatesd

http://cars.about.com/od/thingsyoune...tinjection.htm

...Despite the additional power, EPA fuel economy estimates for the direct injection engine are 1 MPG higher in the city (18 MPG vs 17 MPG) and equal on the highway...

It seems that everyone wants to believe that DI is more fuel efficient, but contrary to what you've read here and elsewhere (I've seen the same misinformation on other websites and in print magazines) GM says...

http://www.cadillac.com/cadillacjsp/model/po_specification.jsp?model=cts&year=2009&section=Powertrain

EPA Estimated 18 MPG City and 26 MPG Highway (RWD 3.6L non-DI Auto model)
EPA Estimated 17 MPG City and 26 MPG Highway (RWD 3.6L DI Auto model)

Note: DI is estimated to have a 1 mpg advantage for AWD, Highway only.