Will the speed limits ever go up?

Consumption at speed

It is the speed that mainly determines the consumption. For a high speed you have to give a lot of gas. The faster you are in relation to the flow of traffic, the more often you have to brake again and again and drive slowly until the lane is clear. That means the cut sinks. The cruising speed is usually well below the desired speed.

I used to assume that consumption decreases with increasing speed, because the engine is then operated for a shorter time, unfortunately it behaves differently, as the diagram shows:

  • Depending on the course the engine uses more or less gasoline. In high gear, i.e. the one with the highest number, consumption is lowest, it is because the engine is at the lowest speed there. The following analogy: the louder the engine, the higher the consumption.
  • When driving slowly if you need a low gear, consumption increases because the speed is high and the engine is only operated in the partial load range.
  • The faster you go the higher the speed, so the consumption increases. At the same time, the car overcomes increasing air resistance.

Safety at high speed

The risk of accidents increases at high speeds. The distance is essential. What happens if someone cuts in on the trail? Then you have to brake hard. Evasion is taboo. No one can make sure that the lane is clear so quickly. Think of overtaking motorcycles.

In addition, the braking distance increases with the speed. Because at high speed, more distance is driven per second. In addition, the energy increases quadratically with increasing speed. The brakes have to destroy more energy in the event of an emergency stop. The braking distance is extremely long at high speeds.

This calculator shows the distance traveled per time. You specify a speed and a time, then you can see how many meters have been driven. In addition, you can press the brakes, then the vehicle brakes. The braking force corresponds to an average motor vehicle on a dry road. A response time of 1 s is also assumed. Note the braking distance, so keep your distance.

The next are speed limits; you have to adhere to them, otherwise you might get a fine. In every country there are specific speed limits and different severity of controls and fines. Ask this beautiful advisor from ADAC.

Consumption at speed in the diagram

This diagram assumes constant speed and shows consumption. The x-axis shows the speed, the y-axis shows the consumption. It is driven in different gears.

You can clearly see that the consumption decreases significantly in high gears. This is due to the low speed at constant speed. You can get an idea of ​​the speed with the lowest consumption. This diagram is decisive for the choice of gear and speed. You should avoid high speeds on motorways in order to achieve low route consumption.

On this page are the parameters used in the diagram, as well as other simulations.

Annotation:
  • switch to the next gear early, this is the lowest consumption, because the speed is so low, you can hear the engine is quietest there. You change to the bottom line as soon as possible. If strong acceleration is required, the engine can rev up and allow high consumption.
  • avoid high speed. They are poison for consumption. Usually you don't arrive a bit earlier due to speed limits, construction sites and the traffic. 60 to 100 km / h is the most economical range.