The function of the product under consideration is to provide a D2842 LE622 industrial diesel engine for use in rail vehicles. An industrial engine with a mass of 1.745 t was defined as the functional unit. The analysis covers the engine’s entire life cycle (“cradle-to-grave”), including the life cycle stages of production or remanufacturing, use, and disposal. For both new and MAN Genuine remanufactured engines, identical functionality is assumed in terms of power output, fuel consumption, emissions performance, warranty, and maintenance intervals. The assumed service life is six years or 20,000 operating hours, which corresponds to a mileage of approximately 1,300,000 km.
Demonstrable Environmental Advantage of Engine Refurbishment
Using the example of the MAN D2842 LE622
The professional refurbishment of diesel engines can make a measurable contribution to resource conservation. A life cycle analysis carried out by the University of Bayreuth and critically reviewed by DEKRA using the example of the MAN D2842 LE622 shows that the MAN Genuine Remanufacturing of an engine causes significantly lower greenhouse gas emissions in production and delivery than a new production. The comparison makes it clear what potential lies in extending product life cycles – especially where existing drive systems continue to be used reliably in the long term.
Preserving resources instead of replacing them
Why engine remanufacturing is becoming increasingly important
Combustion engines will continue to be needed in many applications in the future. At the same time, the requirements for the efficient use of resources and for a transparent assessment of environmental impacts over the product life cycle are increasing. MAN Genuine Remanufacturing of existing engines offers a concrete approach to this: instead of manufacturing an engine from scratch, suitable components are tested, refurbished and reused. As a result, existing resources remain in the economic cycle for longer and the need for new materials and additional manufacturing processes decreases.
For many years, MAN has been reconditioning engines in Nuremberg that have been reliably in use for a long time and have been stressed by daily operation, and putting them back into use. In order to scientifically assess the ecological benefits of this approach, a comparative life cycle analysis was carried out. Using the example of a newly manufactured MAN D2842 LE622, it examines how the environmental impact differs from that of a MAN Genuine remanufactured engine of the same type.
The study at a glance
Scientific comparison of new engine and MAN Genuine remanufactured engine
For the study, a newly manufactured MAN D2842 LE622 and a MAN Genuine remanufactured engine of the same type were compared. Both engines have identical technical characteristics and perform the same function in railway use. This makes it possible to look at the influence of new production and remanufacturing in a targeted manner.
The life cycle analysis was carried out according to the methodology of DIN EN ISO 14040/44. The relevant life cycle phases were considered within the defined scope of investigation – from raw material extraction, material production and production to logistics and use to end-of-life treatment. The modelling was carried out using the "LCA for Expert" software. For production in Nuremberg and reprocessing, specific process data from MAN was taken into account – for example, on the materials used, energy requirements, transports and the waste generated.
The critical review was carried out externally by DEKRA.
The results
Significantly lower environmental impact thanks to MAN Genuine Remanufacturing
The Life Cycle Analysis (LCA) carried out confirms the considerable environmental advantage of a MAN Genuine remanufactured engine compared to a new one. In the life cycle phases of production and delivery alone, the climate impact is reduced from 8,320 to 2,355 kg CO₂ equivalents. This corresponds to a saving of 5,965 kg CO₂ equivalents or 72%. Reprocessing thus makes a significant contribution to resource conservation and the reduction of greenhouse gas emissions.
- 72 percent less greenhouse gas
The difference is 5,965 kg CO₂ equivalents compared to a new production. - 80 percent less virgin material
In a direct comparison, the demand for new material decreases from 1,745 kg to 344 kg. The decisive factor is the reuse of suitable components. - 87 percent less transport capacity
The transport capacity of the components will fall from 99,033 to 12,511 tonne-kilometres. This also creates advantages in upstream logistics.
Long-term effect over several life cycles
Environmental benefits grow with every refurbishment
The study also looks at scenarios over several usage cycles. In a scenario with a one-time refurbishment, a new engine is reused as a MAN Genuine remanufactured engine after the first phase of use. Compared to a scenario with two new engines, greenhouse gas emissions are reduced by 33 percent. At the same time, the use of components is reduced by 44 percent and the transport of components by 47 percent.
In another scenario, the engine is professionally remanufactured and reused a second time after the initial refurbishment. Compared to a scenario with three new engines, greenhouse gas emissions are reduced by 45 percent. The use of components is reduced by 58 percent, and the transport of components by 62 percent.
The results show that the longer an engine can be kept in use through professional reconditioning, the greater the impact on the savings in materials, logistics and production-related greenhouse gas emissions.
Why refurbishment creates advantages
The most important lever lies in the use of materials and production
In contrast to the new production of an engine, which requires the use of raw materials, energy, transport services and extensive manufacturing processes, MAN Genuine Remanufacturing is based on the reuse of suitable components. By testing, cleaning and reconditioning the components as well as replacing them as needed, an existing engine can be put back into use. The resulting environmental benefits are due in particular to the lower demand for virgin materials, reduced transport costs and avoided production-related emissions.
Same function. Different environmental balance.
Technically comparable, ecologically different
An essential aspect of the study is the comparability of the engines considered. The subject of the comparison is a newly manufactured MAN D2842 LE622 and a MAN Genuine remanufactured engine with identical technical function and the same intended use. Differences in the determined environmental impacts therefore do not result from deviating performance characteristics or application profiles, but exclusively from the way in which the engine is made available – either as a new production or by way of professional reconditioning.
Remanufacturing should not be seen as an alternative to technical requirements or product quality. Rather, it enables the continued use of suitable existing components, thereby reducing the need for resources and the environmental impact associated with the provision of an engine.
Circular economy in existing business
A contribution to the resource-efficient use of existing drive systems
The results are an example of the contribution that refurbishment can make to existing business. Especially in applications where combustion engines are still required, it can reduce environmental impacts and make existing resources usable for longer.
For customers, the study creates a transparent basis for decision-making. Using a specific engine, it shows how refurbishment compared to new production affects greenhouse gas emissions, material use and transport performance.
The example of the MAN D2842 LE622 illustrates the potential of extending product life cycles.
Scientifically sound and independently tested
Transparency creates trust
The life cycle analysis was carried out by the Chair of Environmentally Friendly Production Engineering at the University of Bayreuth. The critical review was carried out by an independent external expert on behalf of DEKRA Assurance Services GmbH.
The study follows the life cycle assessment methodology according to DIN EN ISO 14040/44. The inspection was carried out on the basis of DIN CEN ISO/TS 14071 or DIN SPEC 35803.
The Chair of Manufacturing and Remanufacturing Technology at the University of Bayreuth conducts research and develops innovative solutions for sustainable industrial production. The research covers various areas of manufacturing technology, including additive manufacturing, machining, and circular economy concepts. The goal is to design production processes and products that are efficient, resource-efficient, and future-proof.
Sustainability is an overarching, cross-cutting theme in all research activities. One aspect of this is the assessment of environmental impacts using life cycle assessment (LCA). By examining the entire product life cycle, environmental impacts are made transparent, and opportunities to reduce emissions, resource consumption, and waste are identified. The chair combines research in production engineering with methods of sustainability assessment, digitalization, and data analysis to provide scientifically sound decision-making foundations for industry and society. In close collaboration with companies and research partners, practical solutions are developed for the creation of resource-efficient manufacturing processes, durable products, and closed-loop material cycles. With this interdisciplinary approach, the chair contributes to the transformation of production toward a climate-friendly, resource-efficient, and circular industry.
DEKRA Assurance Services GmbH advises, reviews, and audits companies worldwide in various areas of sustainability and environmental management, as well as in chemical regulations, data protection, and information and cybersecurity. As part of life cycle assessments (LCA), DEKRA Assurance Services GmbH conducts critical reviews to evaluate the methodological quality, transparency, and traceability of the studies. This involves verifying whether the conduct and documentation of the LCA comply with relevant norms and recognized scientific standards—in particular ISO 14040 and ISO 14044. The critical review serves to independently evaluate the methods, assumptions, data, and results used. It strengthens the credibility and validity of the study and supports its transparent communication to customers, partners, and other stakeholders. Through its comprehensive expertise in sustainability assessment and independent review, DEKRA Assurance Services GmbH makes a significant contribution to quality assurance as well as to strengthening transparency and trust.
STUDY STRUCTURE AND DATA BASIS
The study considers two reference years: the initial production of the engine in 2013 (the last year of production for this series-production engine) and its remanufacturing in 2023. The background data consists primarily of current datasets, while the primary data for remanufacturing is from 2023.
The life cycle assessment was prepared using the LCA for Experts software (Sphera). SlimLCI+ was also used for automated model creation. The background data comes from the LCA for Experts database as well as from the Volkswagen Group’s internal database LEAD_DB_EN_CUP_2023_2_v2.GaBiDB, which provides Group-wide standardized data sets and links between components and GaBi data sets.
Allocations, i.e. the methodical assignment of environmental impacts to individual products, processes or life cycle stages, are avoided as much as possible through detailed modeling of product systems or through system extensions. If an allocation is necessary, environmental impacts are preferably assigned based on physical properties such as mass or energy content. If these cannot adequately represent the environmental impacts, economic value or quantity is used as the allocation criteria.
The cut-off approach is used to model the disposal life cycle stage. This approach considers only the environmental impacts within the product system under consideration; no credits are awarded for the provision of secondary materials. This approach was chosen because the study focuses on the assessment of reprocessing rather than on the benefits of material recycling.
SYSTEM BOUNDARIES
This life cycle assessment examines the entire life cycle of the product system under study and thus follows a cradle-to-grave approach. The system boundaries encompass the life cycle stages of production, use, and disposal. The analysis takes into account resource extraction, material production, external and internal component manufacturing, transport and logistics processes, engine assembly, fuel supply, and operation during the use phase, as well as maintenance activities and the final disposal of the engine. The study covers the new production of the engine at the Nuremberg (Germany) site, its remanufacturing in Nuremberg, and the reconditioning of the crankcase and cylinder head in the Czech Republic. Upstream supply chains are considered on a global scale, while use is modeled within Europe. The production and reconditioning technologies considered reflect the state of the art in the respective reference years.
RESTRICTIONS
It is important to note that Life Cycle Assessments (LCAs) are complex assessments that require numerous specific methodological as well as data-related decisions by the preparer. All these decisions influence the results of the environmental impact assessment. Differences in deployment profiles, top-down/bottom-up data aggregation methods, data quality, databases used, etc. can lead to variations in results.
These factors must be taken into account when comparing the results of this study with LCA studies from other OEMs. For a fair comparison of environmental performance, the scope, system boundaries and underlying assumptions must first be understood and aligned – even if the same standards are applied. A direct comparison of the results of different studies is not possible without taking these differences into account.
This LCA is based on a typical engine configuration and uses established assumptions for the use and end-of-life phases, which together form a reference scenario. In practice, however, different engine configurations, operating conditions and end-of-life scenarios may occur that can lead to different results. This should be taken into account when using and interpreting the results of this study.
FREQUENTLY ASKED QUESTIONS
A Life Cycle Assessment (LCA) examines the environmental impact of a product over defined life cycle stages.
Because many engines are used in the railway sector over very long life cycles, the large installed base offers considerable potential for CO₂ savings. Professional refurbishment can make existing resources usable for longer and significantly reduce production-related emissions compared to new production.
No. The specific savings depend on the respective engine type, the materials used, the scope of reconditioning, the transport routes and the application profile considered. However, the study on the MAN D2842 LE622 basically shows that the professional refurbishment of engines can provide significant environmental advantages compared to new production.
No. A MAN Genuine remanufactured engine meets the same technical requirements as a comparable new engine. As part of the remanufacturing process, suitable components are tested, refurbished or replaced so that the engine can be used reliably again and perform the same function in the respective area of application.
Yes. The same warranty conditions apply to a MAN Genuine remanufactured engine as to a comparable new engine.
Engine reconditioning is particularly advantageous in areas of application that are characterized by long service lives, an extensive inventory and high demands on the availability of the drive systems. These include, for example, railway applications, workboats for commercial shipping, stationary systems for energy generation and combined heat and power generation, as well as commercial vehicles in long-distance and long-distance transport.