The horsepower of the Smart Forfour 1.0 63HP is by 8 horsepowers bigger in relation to the Mitsubishi. While the difference is small this should not affect the car performance largely.
The width of the vehicle influences directly on passanger's inner room as well as driving stability. The Smart Forfour 1.0 63HP is 49 mm wider in comparison to the Mitsubishi Colt II. It is often clearly felt by driver and passenger in front, who have more space for their elbows.
Smart Forfour 1.0 63HP has 6 % longer wheelbase in relation to the Mitsubishi Colt II. A longer wheelbase provides more stable and comfortable ride, especially at higher speeds. It also gives more storage space. However, vehicles having a longer wheelbase will not be as maneuverable as those with a shorter length between its axles.
Number of doors
The three-door model of Mitsubishi is easy to load and unload luggage into a trunk, whereas 4-door Smart Forfour offers more convenient getting into the car, more quiet cabin at the expense of smaller boot lid.
If you are a tall man or you happen to carry in the trunk thinks of big size, the Smart Forfour, which is by 6 % higher than the Mitsubishi Colt II 1.2 EL,GL 55HP, would be appropriate option for you. However, these two cars do not differ much when it comes to its height and it should not be much perceptible.