Modern city bus driving on deserted new street in desert-like environment

DIWA automatic transmissions for city and intercity buses

Economy and environment in focus: DIWA automatic transmissions for buses

    Accelerate, shift, brake, shift. City bus operators face numerous challenges on the road each day. As a bus manufacturer or operator, rely on Voith’s globally successful DIWA automatic transmissions. With DIWA, you can benefit from 50% less shifting and reduced downtime, maintenance costs and fuel usage.

    Today, over 300,000 city and intercity buses worldwide use a DIWA automatic transmission. Millions of passengers enjoy a more comfortable ride with less noise. At speeds that require other transmissions to shift two to three times, Voith offers you the benefit of stepless accelerating and braking.

    Contact our experts Brochure DIWA NXT

    Your benefits

    • Lower fuel consumption
    • Reduced air and noise pollution 
    • Maximum comfort for passengers
    • Low maintenance costs
    • Lower installation effort
    • Global market leader in CNG buses
    • Meets the needs of demanding BRT systems worldwide


    The right transmission.
    At the right time.


    DIWA NXT is the consistent response to the growing demand for environmentally friendly drive solutions. Thanks to its hybrid system, the automatic transmission closes the gap to alternative drive systems and achieves fuel savings of up to 16%. DIWA NXT offers fleet operators and drivers a wide range of options in a solution that is efficient, comfortable and quiet.

    DIWA NXT: Automatic transmission for all bus operation

      DIWA NXT transmission with central recuperation unit

      DIWA NXT is the next generation transmission for city and regional busses and coaches. It is optimized in terms of efficiency with a 2nd overdrive, a separate retarder and an optional Central Recuperation Unit (CRU) based on 48V technology to keep fuel consumption as low as possible.

      The DIWA NXT is a mild hybrid system with various advantages. It is highly integrated into the flywheel housing of the engine and works with a specifically developed inverter, which is located on the top of the transmission to avoid line losses. A specifically designed battery and cooling system including an optimized DC/DC converter is available. The 48V mild hybrid system is developed specifically for buses and carries out various functions like stop-start, coasting, recuperation during braking procedures or even boosting-support. The new DIWA NXT is one of Voiths answers on the increasing demand for efficient and green driveline technologies and helps to bridge the gap between Diesel and alternative drivetrain technologies.

      • World-premiere: performance of differential converter and retarder can now be independently optimized
      • Recuperates braking energy based on a highly-integrated 48V mild-hybrid system
      • Reduces fuel consumption by up to 16%
      • Reduces air and noise pollution
      • Seamless hardware-software integration from one provider: Voith Digital Ventures

      It´s time for NXT.
      savings through the transmission up to
      reduction in fuel consumption up to
      savings through the hybrid system up to

      DIWA.6 automatic transmission

        Two modern red double-decker buses at a bus stop

        Whatever your requirements as a bus manufacturer or operator, with Voith you’ll find a suitable DIWA automatic transmission that lowers your fuel consumption and decreases your carbon footprint.

        Destination: 100% economical – DIWA.6

        The DIWA.6 automatic transmission is the global standard for economically advantageous and sustainable city and intercity buses.
        Together, intelligent acceleration management and need-based reduction of operating pressure reduce fuel consumption by up to 5%.
        As a bus manufacturer or city bus operator, you profit from a dramatic increase in the transmission’s efficiency.

        DIWA.6 Animation

        Your benefits at a glance

        • Optimized fuel-efficiency
        • Lower air and noise pollution
        • Maximum passenger comfort and safety
        • Tried and true stop-start technology
        • Lower maintenance and installation costs
        • High degree of reliability and availability


        Stop-start technology for DIWA.6

        Better for the environment:
        Our stop-start technology for your DIWA.6 transmission

        City buses spend up to 40% of their operating time in idle mode. Tried and tested worldwide, Voith’s stop-start technology uses this downtime to greatly reduce fuel consumption and emissions. Do your part to combat climate change while making public transportation more attractive.

        • Proven in operation in more than 1,500 buses
        • Reduces fuel consumption by up to 12 %
        • Reduces air and noise pollution
        • Greater riding comfort for drivers, passengers, pedestrians and residents
        • Software for easy updates

        DIWA EfficiencyPro

        Modern covered bus depot in Asia with long line of buses

        The intelligent path to even lower fuel consumption

        Voith is always coming up with new ideas: DIWA EfficiencyPro is a software enhancement that enables eco-friendlier driving and lowers fuel consumption. City bus operators can instantly experience additional fuel savings of up to 4%.

        DIWA product features

          Functional principle DIWA automatic transmission

          Voith automatic transmission for buses - Comparison scheme of the DIWA functional principle
          Specially developed for public transit buses, these transmissions are a must-have for economical operation: Reduced complexity and less installation effort for the manufacturer, lower fuel consumption and rock-bottom maintenance and service costs for the operator. And not only today - but for the entire service life of the bus.
          Learn more about how it works in our detailed videos



          For operation managers in local puplic transport who have to reduce operational cost (fuel consumption as a major cost driver), our OnEfficiency.SmartAccelerate is a software configuration upgrade for your DIWA transmission, which helps to reduce significantly and sustainably fuel consumption.

          LEARN MORE ABOUT OnEfficiency.SmartAccelerate


          The topography-dependent shifting program continually evaluates all key information from the control unit, such as acceleration, load, grade of the road, and dynamically determines the optimum time to shift.

          SensoTop’s abilities have been proven in countless applications worldwide. Depending on topography and vehicle application, real-life potential for fuel savings have been up to 7% compared to an optimized, acceleration-dependent shifting program.
          This leads to a noticeable drop in operating costs. SensoTop also actively helps protect the environment by reducing carbon and particulate matter emissions.

          E300.1/E310 Control Unit

          Voith’s family of transmission control units represents in-house developments that don’t just fulfill the latest automotive standards, but also perfectly meet Voith’s vigorous requirements for automatic transmissions in city buses. Processing power and memory are perfectly balanced against great value and performance. The tilt sensor captures the grade of the road, laying the foundation for the topography-dependent shifting program, SensoTop.
          Beyond connecting to the vehicle, multiple interfaces link to electronic type plates installed in the transmission. Diagnostic interfaces grant access to the control unit via a diagnostic tester and a telematic control unit (TCU) to transmit data remotely.

          The TCU’s software is also developed in-house at Voith. It upholds the highest safety standards and protects the unique DIWA function our customers look for.

          ALADIN from Voith


          The tried and tested diagnostic tool for all DIWA generations enables detailed diagnostics of the transmission and its components. Error data can be read out, and operating data analyzed and interpreted. This aids optimization and power train design.


          Questions? We are here to help.

            Contact our experts

            International DIWA references

              Worldwide, bus operators large and small value the fuel savings made possible by Voith’s innovative DIWA transmissions. These transmissions have the ability to flexibly adapt to a range of infrastructure and topography specifications, which makes them usable in almost any market. This is especially true in emerging markets such as Africa, where the demand for public transportation is continually rising.

              Current distribution of the 160,000 DIWA transmissions used worldwide
              A world map shows the distribution of currently 150,000 DIWA automatic transmissions used across the globe
              Nicholas de la Rosa
              In my 17 years at Manatee County Fleet Services Division, Voith's DIWA transmission for buses have proven themselves time and again. They are just incredibly durable. We've always had great support from Voith, too. These transmissions are well worth the investment.
              Nicholas de la Rosa, Fleet Maintenance Superintendent, Manatee County Fleet Services Division

              DIWA in bus rapid transit systems (BRT)

                Two red BRT buses driving in separate lanes in Bogotá
                TransMilenio, Bogotá, Columbia
                – Market share Voith: 84 %

                Since TransMilenio’s launch, driving times have dropped by 32% and emissions by 40%. The TransMilenio BRT system transports around 2 million passengers each day, making it one of the most efficient BRT systems worldwide. Today TransMilenio is considered a benchmark for many cities worldwide looking to introduce a BRT system.

                Multiple buses stopped at a BRT operation in Brisbane in separate lanes in a large bus depot
                Brisbane Busway in Australia
                – Market share Voith: 63 %

                The Brisbane Busway BRT system exemplifies how DIWA transmissions and services, as part of DIWA Excellence, increase driver comfort and overall safety. Using CNG (natural gas) also helps considerably reduced emissions from the start.

                Voith is a CNG-powered bus leader

                  Bus at a natural gas station

                  Environmentally-friendly operations in North America

                  When phase two of the GHG regulations went into effect with the aim of reducing greenhouse gases in North American cities, there was a clear uptick in demand for climate-friendly CNG systems. Today, over 400 DIWA.6 transmissions are used in CNG engines throughout North America – a number that keeps on growing.
                  A row of modern new buses

                  Establishing a modern transportation system in Baku, Azerbaijan

                  For the first European games in Baku in 2015, 300 new buses to transport fans were equipped with Voith’s DIWA.5 and DIWA.6 automatic transmissions. This marked the start of the city’s modern public transportation system. 

                  Our Service - Part of Your Business

                    Why use Voith Service?
                    Why use Voith Service?

                    • Everything from a single source: development, design, production – and service!
                    • Decades of product experience as an original equipment manufacturer and service provider
                    • Fast and smooth cooperation and best service thanks to a worldwide network of service locations
                    • Long-term partnership and planning security are guaranteed due to longstanding corporate stability

                    To our entire service portfolio

                    Further quality power train products from Voith

                      Future-orientated solutions for buses

                      Drivetrain Excellence - Voith Electrical Drive System for buses
                      Drivetrain Excellence - Voith Electrical Drive System for buses

                      The perfect drive system for changing intra-urban mobility: As an established system supplier with many years of experience and a partner to the bus industry, we have combined our comprehensive know-how in the fields of drive systems and E-mobility. Voith has developed a pioneering electrical drive system for local public transit. The Voith Electrical Drive System (VEDS). 

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