# SteigUm.de — Fact Check

## You can't imagine that driving a car is really that expensive? Then convince yourself. We will show you how we calculate, what data is used and how the result should be interpreted.

Using a car or bike incurs costs that vary depending on the type of vehicle. The ADAC carried out a detailed analysis of the cost structure for each car model and published it in a study. We refer to this study for our calculations (you can find the link below in the sources). The costs break down as follows:

• Fixed costs (liability insurance, vehicle tax, car insurance and a flat rate for parking, maps, technical safety check (TÜV) and small accessories)
• Operating costs (average fuel consumption, average fuel prices, flat rate for laundry and maintenance)
• Operating costs (fuel prices, maintenance)
• Depreciation (calculated over 5 years for a new car; different figures may apply for used and leased vehicles)

The result is a monthly average cost in cents/kilometer broken down individually for each car model.

We have selected three car models in each category, respectively

• Compact Car
• Mid-Size Car

The details can be found in the table below. We determined an average value from these three models for each category, so that we end up having a value per category as a result which we can calculate with.

The cost of a bike is 10 cents/km. This value is based on the study by the Federal Environment Agency.

This brings us to this overview:

• Bike: 10 Cents/km
• Compact Car: 56 Cents/km
• Mid-Size Car: 76 Cents/km

What are the monthly savings when using a bike compared to using a car?

In order to calculate the monthly savings of biking compared to driving a car, some assumptions have to be made:

• 20 working days per month
• 225 working days per year
• Distances and travel times for cars and bikes result from the user's route planning

We have already listed the costs per km for the respective vehicle above. Now, simply multiplying the cost per km by the distance traveled gives the cost per month and year.

The difference in the costs of the two vehicles gives the savings per month.

How are the comparative values determined?

We calculate with average values of:

• 22€ for a movie ticket for two
• 30€ for eating out
• 1000€ for a holiday trip

#### Driving and Carbon Dioxide (CO2 ‑Emissions)

How are the CO2 emissions of a car calculated?

The CO2 emissions of a passenger car are calculated using the combined test cycle (CTW). This consists of a combination of urban, rural and motorway driving and enables the vehicle's fuel consumption, CO2 emissions and exhaust gases to be converted into uniform units per kilometer (g/km). Other factors include engine type, vehicle size and weight, fuel type and driving style.

Here, too, the ADAC provides detailed data for our vehicle types from the table below. This results in average values for the three categories:

• Compact Car: 127 g/km
• Mid-Size Car: 150 g/km

Type of Car Model Costs per Kilometer CO2 emissions output
Compact Car Mercedes A 180 7G-DCT 64 Cent 125 g/km
Compact Car Audi A1 Sportback 25 TFSI 46 Cent 126 g/km
Compact Car BMW 118i Advantage 59 Cent 129 g/km
Mid-Size Car Audi A3 Limousine 35 TDI 62 Cent 152 g/km
Mid-Size Car Mercedes C200 9G-Tronic 80 Cent 144 g/km
Mid-Size Car VW Arteon 2.0 TDI SCR DSG 74 Cent 155 g/km
SUV/Premium Car Mercedes GLS 400 d 4Matic 9G-Tronic 1,43 Euro 210 g/km
SUV/Premium Car Audi Q8 50 TDI quattro tiptronic 1,28 Euro 216 g/km
SUV/Premium Car BMW X7 xDrive4od Steptronic Sport 1,39 Euro 203 g/km

#### planting trees

What contribution do trees make to reducing carbon dioxide? Trees make an important contribution to climate protection because as long as they grow, a large part of the carbon is bound in new wood tissue. Strictly speaking, however, trees do not bind CO2 emissions, but convert them into carbon and oxygen via photosynthesis.

Studies show a global average of 10kg CO2 emissions per tree per year. A beech is said to convert about 12.5 kg of CO2 emissions per year and to be able to absorb one ton of CO2 emissions, the beech tree has to grow for about 80 years. You can also find this study in the sources below.

We use the global average of 10kg CO2 emissions per tree to give an idea of the amount of carbon dioxide. Much more important than planting trees, however, is the protection of existing forests and the avoidance of climate-damaging emissions.

#### Driving cars and microplastics

How much microplastics is caused by car traffic?

Car traffic is the largest source of plastics in the environment. Microplastics emissions are mainly caused by abrasion from brakes and tires. According to the Umweltbundesamt (German Federal Environment Agency), between 90,000 and 140,000 tons of microplastics are released into the environment every year in Germany alone through the abrasion of car tires. The ADAC calculates an average abrasion per car of around 120 grams per 1000 kilometers. We also use this value for our calculation.

In contrast, according to a study by the Norwegian NILU Institute, bike tires and brakes produce thirteen times less abrasion than a car, resulting in 9.23g/1000km.

How can you avoid generating microplastics?

Drive less by car or switch to biking altogether. This significantly reduces abrasion. If all of Germany were to switch to bikes every day, more than 32 tons of microplastics could be avoided every year.

Sources