What a speed limit in the fight against Putin really brings

Created: 04/14/2022 05:13

Tempo 130: In view of the Ukraine war, the discussion about a general speed limit on German autobahns has flared up again.

© Patrick Pleul/dpa

In view of the Ukraine war, the discussion about a speed limit is picking up speed again.

But how much fuel could it really save and what would that help?

The overview.

Berlin – The introduction of a speed limit on Autobahns has long been the subject of controversial discussion in Germany.* With the Russian war of aggression in Ukraine, the topic is picking up speed again*.

Due to a lower speed, vehicles should consume less fuel and thus less oil imported from Russia.

But what exactly does a speed limit do on German autobahns?

The basic argument for a speed limit is as follows: A speed limit on the Autobahn makes Germany less dependent on Russian oil imports.

That is generally true, but the overall fuel consumption of cars only decreases by about 1.5 to 4 percent.

So does a speed limit even make sense?

A third of imported crude oil from Russia

Germany imported about 81 million tons of crude oil in 2021.

Of this, 35 percent came from Russia, i.e. a good 28 million tons.

According to experts, on average about 0.2 to 0.35 liters of fuel are produced from one liter of crude oil in German refineries, depending on whether it is petrol or diesel.

By the end of 2022, Germany wants to be almost independent of Russia in this area.

According to preliminary data from the Federal Ministry of Transport, cars alone consumed 23.82 billion liters of petrol and 18.3 billion liters of diesel in Germany in 2020.

The transport sector therefore offers great savings potential in terms of oil consumption.

Almost 75 percent of the autobahns in Germany without a speed limit

There is often talk of a speed limit on Germany's autobahns, which are around 13,000 kilometers long.

According to the Federal Highway Research Institute (BASt), the proportion of stretches without speed limits in the entire motorway network is 70 percent.

That means: There is no speed limit on a good 9,000 kilometers of motorway.

In general, the faster a vehicle is traveling, the more fuel flows through the engine.

One reason is the air and rolling resistance, which increases with increasing speed.

Conversely, this means that the more restrictive a speed limit is implemented, the lower the fuel consumption and environmental impact.

Anyone who consumes fuel always damages the environment with carbon dioxide (CO2) from the exhaust - and both quantities help to calculate the savings.

The Helmholtz Association of German Research Centers explains: "If a vehicle consumes one liter of petrol, it emits around 2.37 kilograms of CO2.

If diesel was fueled, it is 2.65 kilograms of CO2.”

The Federal Environment Agency (UBA) does not consider petrol and diesel cars separately on motorways, "because the CO2 emissions of average and therefore typical vehicles are very similar depending on the speed".

The following calculations are therefore based on the assumption that the consumption of one liter of petrol produces 2.5 kilograms of CO2.

Result report: 70 percent of journeys in rural areas by car

To put this in context: the car is the most commonly used means of transport in Germany.

57 percent of all journeys are made by car, in rural areas it is 70 percent.

This emerges from the result report “Mobility in Germany”.

According to the UBA, passenger cars and light commercial vehicles caused greenhouse gas emissions of around 30.5 million tonnes of CO2 equivalents on German motorways in 2020.

The term serves as a unit of measure to standardize the climate impact of different greenhouse gases.

In detail: The calculations have shown that Tempo 130 on the freeway would save 1.5 million tons of CO2 and thus 600 million liters of fuel.

While CO2 emissions account for around five percent of the total amount, this measure only reduces the total fuel consumption of cars by just under 1.5 percent.

Federal Environment Agency: Only a drastic speed limit ensures significant savings

Greater potential for savings can only be achieved with more drastic speed limits: According to UBA, a maximum of 120 km/h on the motorway would reduce emissions by 2.0 million tons of CO2 equivalents per year - that's the equivalent of 800 million liters of fuel.

With a speed limit of 100 km/h, it is 4.3 million tons of CO2 - after all, a good 1.7 billion liters of fuel, i.e. about 4 percent of the total consumption of cars.

The environmental authority points out that the mileage in 2020 due to the corona virus * was lower than in previous years.

For comparison: With the values ​​from 2018, the UBA assumed a saving of 1.9 million tons of CO2 at 130 km/h, 2.6 million tons at 120 km and 5.4 million tons at 100 km/h.

If the fuels filled up abroad and used in Germany were also included, the effect would be "14 percent higher" according to the UBA.

Hoping that German motorists would slow down on their own is proving futile.

According to a presentation by two data providers, German drivers are not driving any less quickly despite higher fuel prices.

However, overall there are fewer cars on the roads, which improves traffic flow.