Managing EGR for MPG

[Compaq888]

Originally Posted by Sludgy

I understand why WAI helps fuel economy. Basically, it allows the engine to suck in a smaller mass of air into the engine throught a wider throttle setting. This reduces manifold vacuum, and therefore reduces engine pumping losses.

Another way to achieve the same effect could be by adding exhaust to the intake. First, exhaust is hot, so it would have an WAI effect. Secondly, it would reduce the O2 content of the intake, so less fuel would be added during closed loop operation.

EGR is often used to reduce NOx emissions. Has any Gassaver tested EGR for fuel economy?

Not always true. I have data to back up that the WAI doesn't always improve fuel economy. I actually lost a bet to Matt doing this. Drove 200miles for nothing too. Well not for nothing. Good experiment.

All cars are different. Some cars with WAI will improve fuel economy while others won't. You have to know what your engine and ecu want. That is what all of us are after.