Managing EGR for MPG

[Toysrme]

EGR will not provide a mileage boost in this case. It reduces power output, which will cause you to do nothing more than use a wider throttle angle to increase power output to previous types of levels.




One thing that you people have not thought about is what the EGR system does. EGR is the absolute bane of any, and all modern preventative maintenance. EGR cakes the entire intake tract, pluemn chamber, throttle body/carb plates with carbon from one end to another. The EGr valves themselves eventually stick, any idle valves that are present are commonly stuck with carbon due to the very small orifaces.
Increasing EGR flow will decrease the amount of time between carbon cleanings which for many cars is noticeable within 9-12 months.

The carbon build-up is also responcible for relatively signifigant horsepower losses due to the decrease in charge velocity it from the carbon build-up in the intake tract. (Outright port sizing & flow capacity is only 50% of a charge equation. Velocity is the other 50%.)



So you're not only cutting power from margionally leaner mixtures, you're also decreasing power over time. *Most* EGR eqipped engines will loose a measureable 5-10bhp loss over a year from a completely clean intake tract, to a dirty one.




Carbon build-up is the cause of so many more modern (Read Japanese/European) makers moving to varriable valve timing, and electronic throttle. To remove EGR systems, and their nessesative minor maintenance issues all-together.