It is not only since greta thunberg’s environmental demonstrations that it has become clear that we need to reduce our CO2 emissions. Even though the transport sector in germany only accounts for a small share of total CO2 emissions, we should try to minimize them. Especially because vehicles with internal combustion engines naturally produce a whole range of other harmful emissions.
- 1 what are the CO2 emissions of a car?. Where does the CO2 emission come from?
- 1.1 what causes the greatest CO2 emissions. What do CO2 emissions depend on?
- 1.2 what about the CO2 emissions of a diesel engine?
- 1.3 how you can help reduce your car’s CO2 emissions
What is the CO2 emission of a car?. Where do CO2 emissions come from?

CO2 is a gaseous end product of combustion. Since most vehicles today still have an internal combustion engine (usually diesel or gasoline), most cars also emit CO2. This is caused by the complete combustion of the long-chain hydrocarbons in the fuel. However, since gasoline and diesel also contain other compounds or gases, it is not possible to determine the CO2 content. compounds with other elements, such as nitrogen or also sulfur, are present, there are also other emissions in addition to CO2. This includes sulfur oxides and nitrogen oxides. With the aid of modern catalytic converter technologies, however, the latter emissions are being reduced further and further. This is also true for very modern diesel cars, which also emit very few other emissions with the help of the adblue additive.
The problem with carbon dioxide, as CO2 is also known, is that it is difficult to bind it in vehicles or to modify it so that it is no longer emitted. Therefore, it escapes, as well as the resulting water, through the exhaust pipe into the air. CO2 is an important climate gas that can lead to an increase in the greenhouse effect in the atmosphere. The thermal radiation of the sun leads to an ever higher warming of the earth’s atmosphere, because the CO2 prevents the surplus heat from being released back into space. For this reason, it is important to reduce the CO2 emissions of your car as much as possible over the kilometers you drive.
What causes the greatest CO2 emissions. What CO2 emissions depend on
If you compare the amounts of CO2 released during different journeys, you come to some astonishing conclusions. For example, the CO2 emissions of an average car over the course of a year are equivalent to a two-week vacation in Majorca. Of course, most of this is caused by air travel, which releases a great deal of CO2 per kilometer, which cannot be compensated for by the large number of people transported.
When driving a car, the engine is of course the main source of CO2 emissions. Other systems only indirectly produce higher CO2 emissions, because they are supplied with energy by the engine. This is done either by the alternator and the electrical system or by a direct drive. In summer, the built-in air conditioner is one of the biggest energy consumers.
Generally, significant amounts of pollutants are emitted whenever the engine is cold-started. For example, there are studies that compare the first half-minute after starting the engine with the emissions on 300 compare kilometers driven (warm engine). This is due in particular to the fact that at this point in time the efficiency of the individual systems, especially those for exhaust gas cleaning, cannot yet work optimally. This is why the use of electric systems for preheating (similar to the glow plugs used in diesel engines) is now being promoted.
What about the CO2 emissions of a diesel engine?
The CO2 emissions of a car with a diesel engine in g/km are generally lower than those of a comparable vehicle with a gasoline engine. However, it should not be forgotten that some vehicle manufacturers have used unfair methods, in particular to improve nitrogen oxide (nox) emissions. In this area, diesel engines are therefore less clean than gasoline engines. In the meantime, however, it can be assumed that the "dieselgate" scams have come to an end and that the latest generation of engines really does have extremely low nitrogen oxide emissions. Another point that plays a role, especially in connection with diesel engines, is so-called fine dust emissions. However, these are now reliably eliminated by modern soot particle filters (dpfs).
How can you help to reduce the CO2 emissions of your car?
First of all, if it is possible, you should not drive your vehicle. In addition, you should think in particular about how to avoid short journeys, because these result in particularly high pollutant emissions. If you want more detailed information, there are numerous online calculators available for your personal CO2 balance sheet.
But what other measures can help reduce your carbon footprint?. First of all, there are the regular and mandatory maintenance and inspections. So your engine can only function optimally if it is regularly refilled with new operating fluids and filters. Other work, such as changing water pumps or timing belts, should also be carried out according to the manufacturer’s specifications. In addition, every system that is switched off also saves CO2. For example, reduce the output of your air-conditioning system so that it is not running at 30 °C outside temperature must cool your vehicle to 20 °C.
By adjusting your driving style, you can also do something to make your engine work more efficiently. And higher engine efficiency automatically leads to lower CO2 emissions. Thus, you should equip your drive unit with 1.500 by 2.500 revolutions per minute. This is where it reaches its highest efficiency. At the same time, they reduce their fuel consumption by about 20%. To achieve this, use from 30 km/h the 3., from 40 km/h the 4. And from 50 km/h the 5. Gear.
Another option is to change the fuel used by your car to a different. This is how many vehicles can be converted to alternative fuels. For example, bio-diesel and bio-ethanol produce comparatively low CO2 emissions.
Conclusion
Make your contribution today to achieving our climate protection targets. by trying to reduce the CO2 emissions per kilometer of your car, you make your own personal contribution. This is particularly advantageous if you are unable to replace your vehicle with a new one, or if you are unable to do so now in a sensible and economically viable manner. We hope that this article has provided you with a suitable guide so that you can drive in a more environmentally conscious manner in the future.
A tip from AUTODOC:
always remember that you do not emit CO2 when you leave your car or switch to an electric vehicle. In the case of the latter, however, the climate only benefits if the electricity used for the car is also generated in an ecologically sensible and climate-friendly manner. For example, you can use the electricity from your own photovoltaic system to charge your car.
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A cheerful mechanic with a lot of experience who participates in AUTODOC’s video tutorials; has never been spotted without his glasses; drives a BMW X5 E53; dreams of receiving a gold play button that comes with the number of 1 000 000 youtube subscribers.