Environmental group report finds diesel still powers 70% of city buses in Germany

Three cities exceed fifty percent electrification

Deutsche Umwelthilfe surveyed municipal bus fleets across Germany's largest cities based on operational data from 31 December 2025. Only three municipalities achieved an electric bus share above 50%, all located in the state of Baden-Württemberg. Mannheim led the national ranking with 60.6% of its fleet powered by battery-electric systems, followed by Freiburg at 51.7% and Karlsruhe at 51.6%. All three top-ranking cities committed to purchasing exclusively electric vehicles for future fleet renewals through 2030. Nürnberg secured fourth position nationwide with a 48.1% battery-electric share.

Diesel predominance and future procurement plans

Across the 39 surveyed cities, conventional diesel propulsion accounted for 70% of operational buses at year-end 2025. When mild hybrid systems are included, combustion-powered vehicles represented 77% of the total urban bus fleet. The environmental organization reported that nearly half of the surveyed cities plan to purchase additional combustion-engine buses between 2026 and 2030. In Thuringia's capital, Erfurt, where electric buses make up under 4% of the fleet, older diesel buses operating below the Euro V emissions standard remain in daily passenger service. More than half of Erfurt's planned bus purchases will feature combustion engines, while Halle plans to purchase combustion vehicles exclusively.

Deutsche Umwelthilfe criticized the continued use of older diesel vehicles in dense transit corridors.

Their nitrogen oxide emissions are many times higher than those of modern Euro VI vehicles. Especially in densely populated urban traffic, thousands of people are directly exposed to harmful exhaust fumes.

Regional variations and alternative drive models

Electrification rates varied widely across regional centres in central and western Germany. In eastern Germany, Leipzig recorded the highest proportion of electric buses at 19.6%, followed by Dresden at approximately 11% and Halle at just over 6%. Five cities registered zero battery-electric buses in their fleets: Magdeburg, Essen, Wuppertal, Krefeld, and Augsburg. In western states, Wiesbaden recorded 40.2%, Frankfurt reached 18.1%, Mainz stood at 14.8%, and Kassel registered 14.0%, placing all four in a category requiring administrative intervention.

A zero score in battery electrification did not uniformly reflect reliance on standard diesel engines. In Wuppertal, hydrogen fuel-cell buses accounted for one-sixth of the municipal transit fleet. In Augsburg, which ranked last in battery-electric adoption, public transit operators have run a 100% biogas bus fleet since 2011.

Fleet expansion strategies and municipal targets

Municipal transit authorities that initiated transition programmes earlier showed higher rates of fleet conversion. In Bavaria, Munich placed 14th with a 16.7% electric bus fleet, while Nürnberg recorded the highest share in the state. Nürnberg transport operator VAG had 123 battery-electric buses operating out of approximately 200 vehicles by the December 2025 survey cut-off date. VAG board spokesperson Tim Dahlmann-Resing described the early municipal policy framework behind the transition.

We looked into a possible switch to electric buses very early on (ten years ago, in 2016) and adopted an electric bus strategy for it.

Following the delivery of 21 additional electric vehicles in 2026, Nürnberg's operational electric fleet grew to 144 units, representing 70% of its total vehicles. The municipal operator plans to complete a 100% conversion of its bus fleet to electric propulsion by 2030.