What is the name of BMW's flagship saloon/sedan series?

BMW’s flagship saloon/sedan series is the 7 Series.

The 7 Series occupies BMW’s full-size luxury-car class and serves as the brand’s top conventional saloon or sedan line. It is positioned above the smaller 5 Series, 3 Series and other BMW passenger-car ranges, combining the company’s latest cabin technology, luxury equipment and powerful engines.

BMW introduced the first-generation 7 Series, known internally as the E23, in 1977. It replaced the large E3 sedans and established the naming pattern that BMW still uses for its flagship four-door luxury cars. Depending on the market, the car is called a saloon or a sedan; both terms refer to the same three-box body style.

The 8 Series is a separate grand-touring and luxury coupe/convertible family, not BMW’s flagship saloon range. The fully electric i7 is likewise related to, and sold alongside, the current 7 Series as its battery-electric counterpart. Historically, high-end versions such as the 760i and 760Li have used V12 engines, although BMW later ended V12 production in this line.