305fan

consider the 2.4L VVT--no DI and 171hp.
By adding DI--200 ho oir damn close should be easy---and impove mileage.

Plague

Take the Lambdas. They get 16-24 without direct injection. With direct injection, they get 17-24.

2008 275hp/251tq
2009 286hp/270tq

The torque jump is pretty good, the hp jump is ok. GM made the vehicle more powerful, but barely more fuel efficient.

In my opinion direct injection should be more about using smaller engines to make the same hp and tq numbers with better fuel efficiency. Then, make a few high end models with it that get nice hp/tq numbers with slim differences in fuel economy, but don't make the big engines be a requirement of those higher price vehicles.

305fan

maybe the small increase in mileage can be attributed to the weight of the Lambadas?

I am thinking a this engine in a Cobalt with a 6 speed auto could get a much better increase.