Although there are some similarities, these two are different in most aspects such as model year, body structure, powertrain, fuel economy, market segment, horsepower, and ground shadow size. First of all, there is a significant difference between body structures and exterior dimensions. The 2018 Clarity Plug-in Hybrid is a Sedan, while the 2021 Leaf is a Hatchback. It is also slightly larger. Also, the Clarity Plug-in Hybrid has bigger and thirstier engine; the Leaf gets 65.6 more mpg. Among similarities are the starting price and maximum occupancy.