The Citroen C-Zero 67HP automatic has 1 Nm more torque in comparison to the Peugeot iOn. Even though most of people do not attach importance the maximum torque when buying a automobile, it describes the best how fast a car acclerates. As far as these two vehicles are concerned the difference is not really big so the difference will not be much noticeable.
Citroen C-Zero has 2 mm longer wheelbase when compared to the Peugeot iOn 67HP automatic. A longer wheelbase gives more stable and comfortable ride, especially at higher speeds. It also provides more storage space. But, vehicles having a longer wheelbase are not as maneuverable as those with a shorter wheelbase.
The Citroen is 5 mm longer in relation to the Peugeot iOn. Long vehicles more of passenger space and in most cases have bigger trunk. While the Citroen C-Zero occurs to be better option for families or those who love the idea of comfortable rides that make them feel fresh and relaxed upon arriving, the Peugeot iOn may be more appropriate to city drivers as it will not cause problems with parking and will be more maneuverable.
If you are a tall driver or you tend to carry in the trunk stuffs of large dimensions, the Citroen C-Zero 67HP automatic, which is by 2 mm higher than the Peugeot iOn, would be better choice for you. However, these two vehicles do not differ much when it comes to its height and it should not be much noticeable.