How to make an entire car’s life more ecologically efficient

Towards a more sustainable Audi with Life Cycle Assessment

Audi uses integrated Life Cycle Assessments (LCA) in the development process to make its new models and processes more sustainable. Blog author Olivia Faulbacher found out why not only exhaust emissions are relevant.

Susanne Then und Olivia Faulbacher arbeitend am Computer
Susanne Then explains the purpose of a life cycle analysis to Audi blog author Olivia Faulbacher using the example of the Audi Q7.

Even before a new Audi covers its first kilometer on the road, it leaves a tire print on the ground – an ecological footprint. Even its birth requires raw materials and energy. To make the production and use phases as sustainable as possible, Audi drew up a holistic environmental balance sheet for all models.

Susanne Then and her colleagues have dedicated their effort and time to so-called Life Cycle Assessments (LCA). “We evaluate the vehicles according to their environmental impact over their entire life cycle – “from cradle to grave”,” says the environmental and process technology engineer.

Audi focuses on a holistic life cycle analysis

This begins with the extraction of the raw materials required for the car’s production. There is a positive influence when recycled materials are used. In addition, the influences of the use phase, i.e. fuel production and driving mode, are included in the balance sheet. We also consider recycling at the end of the vehicle’s life when the car’s components are shredded for recycling.

Heckansicht Audi Q7

Susanne Then and her team create an ecological tire print of different models by overlaying different graphs and thus carry out a comparison. Based on this, they're drawing conclusions – such as the answer to what extent the ecological tire print of a car has sunk compared to its predecessor.

“Our main goal here is to identify points of attack along the entire value chain as to how we can make our entire product more sustainable,” Susanne Then explains. Every new Audi that comes to market should thus cause less environmental pollution than its predecessor. That is why the Life Cycle Assessment Team is already on board in the early development phase of new models and regularly issues environmental forecasts. “In this way, we can influence the development process in a targeted manner.” In the current Q7, Audi has succeeded in reducing greenhouse gas emissions by as much as 16 percent compared to its predecessor.”

What more lightweight construction in the Audi Q7 means for the environment

But let’s start at the beginning: The life cycle of the Audi Q7 begins with its production. In this phase, the focus lies primarily on materials and their weights. “We have used considerably more aluminium in the current Q7. The extraction of raw materials and the production of such light metals are more energy-intensive than of steel, which is why we initially calculate with more greenhouse gas emissions. Due to its lower weight, the new Q7 can drive much more economically on the road,” the engineer explains. It is therefore crucial that this additional expenditure from production and manufacturing recoups as quickly as possible in its next phase of life – the use.

Material inventory Q7 vs Q7 e-tron
The goal of a life cycle analysis is the optimization of the value chain in a sustainable manner. This optimization is based on a holistic analysis of all the important factors.

From the so-called break-even point onwards, the additional emissions brought about in production for lightweight materials pay off, improving the environmental balance of the new Q7 generation’s vehicle with each additional kilometer compared to its predecessor.

 

Cradle to Grave

Audi considers the environmental impact of its cars over their entire life cycle.

This includes the energy and raw materials needed for material and component production and for its own production, fuel production, emissions from driving and the recycling or recovery of recycling materials at the end of vehicle life. Particular focus is on the emission of greenhouse gases. The measured variable is CO2 equivalents, in which all greenhouse-relevant substances that enter the atmosphere are normalized to the value of CO2. Thus, carbon dioxide has the efficiency 1 and methane the efficiency 25, for instance. Aside from greenhouse gases, other effect categories such as the potential of acidification, eutrophication and summer smog are observed. The procedures are uniform throughout the company and are conducted in accordance with the rules of the ISO 14040 ff series of standards and have been validated through an approved independent expert, such as the TÜV.

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Why the current Audi Q7 is more sustainable

“To achieve this goal as early as possible, we are in constant contact with other development engineers during the development process”, Susanne Then says. “If the material or weight of relevant components changes, we calculate the ecological consequences with our accounting tool and point out optimization possibilities.

Frontansicht Audi Q7 auf Straße
CO2 emissions across the entire vehicle life cycle - the Q7 is more efficient than its predecessor after almost 34,000 kilometers.

Because the current Q7 generation is now around 325 kilograms lighter than its predecessor and the engines of the new generation are more efficient, the break-even point is already at just under 34,000 kilometers. Over an average mileage of 200,000 kilometers in operation, this means around nine tonnes less greenhouse gas emissions per vehicle. What a nice success – the effort of the developers was worth it!

But what about hybrid vehicles, such as the Q7 e-tron quattro? Battery materials also play a role here. At the beginning of its vehicle life, for example, it initially produces four tons more greenhouse gas emissions than with a combustion engine. But how does the overhead of battery manufacturing affect hybrid models such as the Q7 e-tron in their entirety?

“The environmental balance clearly shows that electric cars only bring us significant ecological advantages if we operate them with electricity from renewable energy sources, rather than with EU power mix”. As a plug-in hybrid, the Q7 e-tron will then emit less greenhouse gases after just 38,000 kilometers than a comparable Q7 with a conventional drive.

EU power mix

The EU power mix represents the average power supply of the end consumer in the European Union by energy source. This primarily consists of nuclear energy, coal, gas and oil.

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The exhaust view is not everything

The bottom line: In order to make mobility more sustainable in the long term, the entire life cycle of a car has to be considered – the production of vehicle and fuel are just as important as the emissions from the exhaust. “The public and the legislation usually only consider pollutant emissions while driving. Audi looks outside the box,” says Susanne Then. Because from the cradle to the grave of a car’s life, there are even more points of attack that Audi can optimize in the overall context, reducing the environmental footprint of an Audi with every generation.

According to the environmental balance, operating the Audi Q7 e-tron with hydroelectric power proves to be much more sustainable.

Audi Environmental Foundation supports young researchers: award for contributions to resource management
Audi MediaCenter

Audi Environmental Foundation supports young researchers: award for contributions to resource management

The Audi Environmental Foundation and the Technical University of Munich (TUM) have recognized the master’s degree theses of two young scientists with the “Sustainable Resource Management Award.” The SRM Award brings prize money of 1,500 euros and has been awarded to TUM graduates of the Sustainable Resource Management course of study for the seventh time. It particularly recognizes environmentally friendly and sustainable ideas. Prizewinner Daniela Angelova developed concepts for future-oriented urban development and Diana Young developed approaches for more efficient biogas plants.

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Consumption and emission figures of vehicles on this page:

Combined fuel consumption in l/100 km: 6.4 – 1.8; Combined electrical consumption in kWh/100 km: 19.0 – 18.1;  Combined CO2 emissions in g/km: 168 – 48. Figures on the fuel consumption and the CO2-emissions vary in case of given ranges depending on the used combination of wheels/tires. // www.audi.de/DAT-Hinweis

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