Although there are some similarities, these two are different in most aspects such as body structure, powertrain, horsepower, fuel economy, market segment, starting price, and ground shadow size. First of all, there is a significant difference between body structures and exterior dimensions. The 2018 Honda Clarity Plug-in Hybrid is a Sedan, while the 2018 Nissan Leaf is a Hatchback. It is also slightly larger. Also, the 2018 Clarity Plug-in Hybrid has a more powerful engine and gets 70 mpg less than the 2018 Leaf. In addition, there is a $3,410 difference in the base MSRP. The Clarity Plug-in Hybrid has a higher starting price than the Leaf. Among similarities is the maximum occupancy.