[tjts1]

Wow, a lot of gibberish being thrown around here but nobody has any clue what they're talking about. If your car has EGR, disable it temporarily and see how it affects your FE. If you have an OBD2 car and some OBD1 cars, chances are it will trigger a CEL light. Consider yourself warned. To avoid this, the best way to defeat the system is to block off flow at the intake manifold after the temperature sensor. My bet is your FE will improve. The vast majority of cars from the 80s and 90s that had EGR used a simple ON/OFF system. It didn't have a variable flow control. These systems existed to reduce NOx emissions. Thats it. At best, they have a very small negative effect on FE. At worse, they increase fuel consumption by 3-5%. Most newer cars no longer need an EGR system to reduce NOx because they usually have multiple modern catalytic converters and VVT which can be used for internal EGR inside the combustion chamber. No cars use EGR at WOT.