Managing EGR for MPG

[omgwtfbyobbq]

Probably not since the engineers who set-up your engine already figured the maximum amount of heated exhaust that could be added w/o raising the cylinder temp too much, i.e. egr is probably already optimized for fuel economy, unless you don't have it. You could try it, but make sure to keep an eye on the engine and have a cut-off you can use in the car, detonation is never good for an engine. A nice project would be to take a solid old iron block/head engine, retrofit it for SAFI/EGR, and run methanol. Maybe even a turbo if you're so inclined.