Although people are so quick to call this car a D-segment or a stretched-out Genesis G70, it's really a watered-down Genesis G80 with some more liftback vibes. Think about it!!! Its wheelbase is much longer than a Lexus IS and slightly longer than an Infiniti Q50; arguably though, those two cars are outdated and should have been discontinued years ago. The Acura TLX is very, very close in size to the Kia Stinger. Not to mention, it's Korea's take on the muscle-style car recipe, ala the Dodge Charger, much like how the Genesis G80 rivals the Chrysler 300.
Going by my standards, a compact car comes standard with a 3- or 4-cylinder engine displacing 1.5-2.5L (usually without a larger or turbocharged option outside of the 'specialist' performance niche), comes with a 105-110" wheelbase, sports 85-95 cubic feet of passenger volume, and offers 30-35" of rear legroom space.
Likewise, midsize cars (well, okay, there's two types- an 'intermediate' and a 'standard') get standard 4-cylinder engines displacing 2.0-3.0L (with an option for a 5/6-cylinder or a turbo sleeper alternative), come with a 110-115" wheelbase, sport 95-110 cubic feet of passenger volume, and offer 35-40" of rear legroom space.
The Kia Stinger comes with a 2.5L I4 engine, but it is turbocharged. Because the displacement exceeds 2.4 liters (even by a slight bit), I have to multiply by 1.7 instead of the usual 1.4, so 4.2 liters and 6 cylinders (either an I6 or a V6) are the equivalent if the 2022 version of this car were naturally aspirated. That easily places it in E-segment. Even the wheelbase of 114.4" is borderline with E-segment, it's literally barely shy of a current-generation Audi A6/A7!!! Also, it sports 95 cubic feet of passenger volume (segment D) as well as offers 36.4" of rear legroom space (segment C).
Here's the problem, the Kia Stinger isn't a real sedan! It's basically a four-door coupe, so you basically have to multiply by 1.1. You get an actual passenger volume space of 104-105 cu.ft. (derived from the official 95 cu.ft.). The same problem occurred for me with the Mercedes-AMG GT liftback, which is listed at 96 cu.ft (basically 105-106 cu.ft. if it were a traditional sedan; in-between an E/CLS-Class and an S-Class, exactly like how it is officially positioned in Mercedes-Benz's lineup).
The Stinger's 104 cubic feet of passenger volume is only 3 cubic feet off the G80's. It's basically a full-size car.
If A=1, B=2, C=3, D=4, E=5, and F=6, then...:
Stinger: (5+5+5+4) = 19 / 4 = 4.75 (rounded up to segment E). Even though it's 0.6" away in wheelbase from making it fully into the E-segment (it's longer in wheelbase than the Toyota Avalon and Lexus ES), its passenger volume really makes up for it. It's larger than an A6, a 5er, and an Einspritzmotor. It's just as large as a Honda Accord and a Dodge Charger, and a little bit bigger than the Toyota Avalon and Ford Taurus.
Now I know exactly why Hyundai gave up on marketing the full-size Azera for the US and finally decided to rebadge the Genesis (also a full-size car) as its own brand with the G80 trademark. It's all because of the Stinger! 😜