
The new M135 model signifies a shift in BMW's naming convention for its gasoline models by dropping the letter "i" (from "injection") from the name. This change reflects the automaker's strategy to use "i" exclusively as a prefix for electric vehicle names. This is evident when looking at the tailgate of the new M135, which only says M135, omitting the "i" from the name.

The fourth iteration of the BMW 1 Series has undergone significant cosmetic changes while retaining the front-wheel-drive architecture2. The exterior styling is evolutionary, with sharper-looking headlights and rear taillights that resemble those of the latest X2. The M Performance derivative features a quad exhaust system, which is inherited from the X1 M35i and X2 M35i. The new performance hatchback also signals the beginning of the end for the letter "i" in the names of BMW's gas models. Additionally, the performance version boasts M-specific side mirror caps, an M badge on the kidney grille, and an M logo on the plastic engine cover with its fake carbon fiber. The normal 1 Series has a rather odd grille design with interlaced vertical and oblique lines, and traditional door handles instead of the flush ones found in most newer BMWs. The 1 Series is BMW's first car to offer a contrasting roof finish with a glossy black look.

The new BMW 1 Series performance version, the M135, boasts several M-specific features that set it apart from the standard model. Some of these features include:
These M-specific features contribute to the sporty and performance-oriented character of the new BMW 1 Series, making it an attractive option for those seeking a more dynamic driving experience.