the gearbox comes without sports/normal mode or overdrive switch. instead, it comes with what known as Innovative and Intelligent Vehicle Electronic Controls from Mitsubishi or INVECS. now in its 3rd generation, Waja is actually using INVECS II.
its a thinking gearbox. it can upshift and downshift to give us more control over the car instead of the car controlling us (auto spec only). try drive the waja auto downhill and u will feel it downshifting from 4th to 3rd. sumthing the E55 perdana 4 cylinder or C98 wira 1.6 auto cant do.
INVECS II also adapts to ur driving style. if u r driving heavyfooted, the gear changes at higher engine speed to exploit more power from wider speed band.
that's what happen when i drive my father's car. when he gets back to his car, the transmission will adapt to his old man style driving, thus faster gearchange and more economical.
during the transition, we can feel the gearbox like refuse to change gear or wondering which gear to use. actually, that's the effect of ECU thinking whether the driver is still driving fast and spritedly or behaving normally.
SXV20 Camrys also has this feature. not to mention BMWs, Merc or Audis.
the figures u mention here is normal to me. 6,000rpm may not be necesarily the peak power for 4G18.