If it would be an auto, i m not sure it would have more then 3 gears in forward, same as happening in alto, kei, mini pajero etc, other 660cc cars, even daihatsu cuore auto car has 3 forwards in D, so the difference would be like 1 or 2 km/liter will be observed from manual but under 60-70 km/hr of speed, anything like around 100 or above would make these little monsters to eat like 1.8 liter car and mileage dropped distinctly ! observations from alto and kei ...... my personal experience.