[ever_green]

I have 09 impreza 2.5i that's got a modified shortblock. the mods are in the signature but the main thing is that the car makes its peak torque at 4000rpm vs 4500rpm now (on the dyno). Even though the peak torque has dropped, both top end and low end power have been improved so the torque curve is much flatter now. ie. 95% of torque is made at ~2000rpm. For the stock engine subaru BSFC graph claims a sweetspot of 1500-4000rpm at 80-90% load. i think 4000rpm bsfc is no longer the case since my high lift cams engage as early as 1500rpm and car runs rich above 3000rpm now(depending on load). so i have been using the sport shift when in economy mode to improve MPG. i used to be shifting at 3000rpm & allowing the TC to fully unlcok at 80% load. but mileage did not improve, at least around town. so i decided to shift at 2000rpm instead and 60% load. but the torque converter makes this a pain in the butt. with +60% engine load the RPMs jump past 2000rpm as TC unlocks, even when im in overdrive at 25mph! unless i back off the throttle and drive slowly i cannot shift at or below 2000rpm.

just wondering what people's experiences are in shifting an automatic in order to improve fuel economy? drive slowly and let the torque converter slip to shift at low rpms or just let it fully unlock and shift at higher rpms?