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, the is a newer vehicle by 3 model years. Also, body structures are completely different. One is a Sedan and the other a Hatchback. The 2018 Clarity Plug-in Hybrid is also slightly larger than the 2021 Leaf. In addition, the Clarity Plug-in Hybrid has a more powerful engine and gets 65.6 mpg less than the Leaf. Among similarities are the starting price and maximum occupancy.