The classifications are not consistent and often don't mean anything. For example, the Niro is not classified as an SUV by the CAFE standards the OP is talking about. The Insurance Institute for Highway Safety also calls it a small car and a 4 door wagon (https://m.iihs.org/iihs/ratings/vehicle/v/kia/niro-hybrid-4-...)
I have a Kia Niro that is classified as an SUV by the manufacture and insurance company. It gets about 50mpg in the summer. I look at it and compare it to my old 1984 Chevy Citation II. It is almost the same size and the Citation was a "hatchback". Look, your crossover is a station wagon, and a lot of SUVs are just hatchbacks.