Hey all

The latest goal of the mods with my Integra have been strictly for fuel economy. The exhaust system needs replaced (I'm leaving the header and cat) -- but I can't find hard evidence of increasing/decreasing the diameter of the piping, or if a free-flow muffler will drop the backpressure, and then torque drops, etc. I'm afraid to change the stock setup for fear of losing gas mileage.

Is there anyone with some scientific input on exhaust choices and fuel economy?

RH77