5% increased gas mileage

[RETed]

Another area to look at if your ECU can do this is try negative ignition timing split - this is just a fancy way of saying: fire the trailings before the leadings.
There was this big thread on the Evil Forum (I think) talking about this...
I tried it with my Haltech E8, and it does allow you to run slightly leaner AFR's at idle and vacuum cruising.
I believe the numbers were you could gain another 5% - 10% in gas mileage doing this properly.

Now, the cavaet...
Although I was able to do this with my Haltech E8, it wasn't stable enough that I kept at it.
My set-up acted tempermental and sometimes felt like lean surge when cruising under heavy vacuum.
This annoyed me enough to give up trying to get that last few 1 - 2 mpg out of the engine.


-Ted