...the RPM will decrease 500 rpm when I let off of the gas ... is normal... When tranny is warm (20minute drive), on steady crusing maxima gearlock steps in at 3&4th gears. Then from mpg point of view, it is on par with manual box. This gearlock is workin only above that 45mph, and only steady gas. Thus hittin the pedal releases this lock, increases consumption, and will not lock =come back 'until u cool again'...
All this means that 20 minute daily commute never reaps the benefit of this lower 10% consumption -feature. To learn more, clic seek top left 'Favorite links' on page below: