I am coming from the old school OBD1 Tech of the SOHC d16 Engines so am now surprised at he wonderful gas mileage of the 2009 fit (JDM L13A) Engine.

There is always the need to squeeze out the most out of the engine but how does the engine/computer react to mods like cold air intakes.

Does it pull timing to compensate?

Dump more fuel to compensate for more air coming into engine?

Is the performance upgrade noticeable to say, its a must that i purchase a new filter?

Does anyone have Dyno figures to substantiate the responses.

The CAI was the most noticeable performance upgrade on my Old School SOHC Civic and would hope that i can do something just as noticeable to the Fit without killing the mileage. (Want to have my cake and eat it too)