As most of us know-or assume-today’s automobiles have a ‘segment’ in which they fit. For the sake of overview, we’re listing them here, with examples:

Full Size Pickups: Ford F-Series, Dodge Ram, Toyota Tundra, Nissan Titan, Chevrolet Silverado
J: Sport Ute and Crossovers
M: Minivans; multi-purpose vehicles (Mazda5, Nissan Quest, Toyota Sienna, Honda Odessey,Kia Sedona, Chrysler Town and Country)
S: Sport Coupes
F: Full-size, well-equipped. Some Rear-wheel-drive with All-wheel-drive option; some Front-wheel-drive with AWD option. (BMW 7-Series, Mercedes-Benz S-Class, Audi A8, Lexus E350-Infiniti-Acura)
E: Full-size non-luxury (Toyota Avalon, Chevy Impala, Ford Taurus Subaru Legacy, Hyundai Azera, Nissan Maxima, Chrysler 300). These vehicles no longer dominate.
D: Family car of choice. Midsize (Nissan Altima, VW Passat, Chevy Malibu, Chrysler 200, Dodge Avenger, Ford Fusion, Honda Accord, Hyundai Sonata, Kia Optima, Mazda6, Mitsubishi Galant
C: Compacts (VW Jetta, GTI, Hyundai Elantra, Honda Civic, Kia Forte, Mazda3, Toyota Corolla, Nissan Sentra, Subaru Impreza)
B: Subcompacts. Super mini, city car (Honda Fit, Kia Rio, Chevy Aveo, Toyota Yaris, Chevy Sonic, Mazda2, Ford Fiesta, VW Golf, Mini Cooper, Fiat 500)
A” Mini cars, micro cars (Tata Nano, SmartForTwo). Smallest on the road; An emerging market; ‘city car.’ They seat 2-4, often 3-cycle engine.