would an aftermarket piggy back system like the Apex'i AFC fuel controller work with the landcruiser ECU? anyone ever thought or experience with trying to lean out the tune, to try to get better gas mileage? this is of course with a guidance of a wideband meter of some sort for a/f safety. any idea what a good a/f range should be? at idle, cruise and WOT (wide open throttle)? i know on my old 95 supra turbo, we tuned it to 15-16:1 a/f ratio at idle and cruise. WOT (wide open throttle) is 11.5:1 for safety i had 750whp but was still able to get 25 mpg if i cruised easily on the highway!