[5] Following a $250 million development program by Freightliner, the Business Class M2 was introduced at the beginning of 2002; starting with 2003 production, the all-new model line was gradually phased in as a replacement of the previous FL-Series.

[6] In contrast to the FL-Series, which adopted a Mercedes-Benz low-cab COE to a conventional-cab configuration, the M2 was developed within North America.

[8] Following the exit of both Caterpillar and Mercedes-Benz from on-highway diesel production in North America, the model line sourced its engines exclusively from Cummins.

[11] In 2006, Freightliner produced its first prototype of a diesel-electric parallel hybrid vehicle, using a M2 106 powered by a Mercedes MBE906 diesel and an electric motor integrated within the drivetrain.

[12] The system was intended to move from a stop on electric power, with the diesel engine providing only supplemental torque.

[12] The parallel-hybrid configuration entered production in 2008,[13] with Freightliner targeting customers driving in urban environments.

[17] Following field testing of limited-production vehicles by customers,[18] the eM2 entered full-scale production in 2023 as a variant of the second-generation M2 Plus.

[5] Visibly similar to the first generation, the Plus series is distinguished by its projector headlamps, an enlarged hood vent, and a restyled grille (replacing its Century Class-style design with the slatted style of the facelifted Cascadia).

[20] Though sharing the cab structure of the previous generation, the interior of the M2 Plus was completely redesigned, centered on upgrading both ergonomics and user technology.

[5][21] An all-new dashboard integrated functions into the steering wheel, increased the customization capability (for auxiliary switches), and a largely digital instrument panel.

[26] The model line adopted the cab structure of the M2 (reinforced by steel[25]), placing it on the chassis of the 122SD (the renamed Freightliner Coronado).