Kinematic chain, fuel consumption and eco-driving
If you understand your engine, you drive more cheaply and with less impact on the environment. This topic covers torque, power and consumption curves, driving resistances and an anticipatory, economical driving style in line with the CZV and VRV.
- 26 questions in this topic
- Topic 7 of 13 in the course: CZV – certificate of professional competence for goods and passenger transport: theory exam
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From the key facts
- The syllabus includes torque, power and specific consumption curves as well as the optimum engine speed range (CZV Annex no. 2.111).
- Power is the product of torque and engine speed: the same power can be produced with high torque at low engine speed (physics; CZV Annex no. 2.1111–2.1112).
All key facts, the questions with explanations and the exam simulation are part of the course.
Sample questions from this topic
3 of 26 questions free to try. All questions with explanations and the exam simulation are part of the course.
Question 1: What does the torque curve of an engine describe?
- The engine's oil consumption per 1000 km
- The pulling power of the engine at different engine speeds
- The maximum speed in each individual gear
Show answer
Correct answer: The pulling power of the engine at different engine speeds
The torque curve shows how much torque (pulling power) the engine delivers at which engine speed. It is one of the basics of the kinematic chain.
Legal reference: CZV Annex no. 2.1111
Question 2: How are engine power, torque and engine speed related?
- Power = torque times engine speed
- Power is independent of engine speed
- Power = torque divided by engine speed
Show answer
Correct answer: Power = torque times engine speed
Power is the product of torque and engine speed. That is why an engine with high torque can deliver a lot of power even at low engine speed.
Legal reference: CZV Annex no. 2.1111–2.1112 (physics)
Question 3: What does the specific consumption curve (consumption map) of an engine show?
- How many kilometres are left until the next service
- How much fuel is used per unit of energy produced
- What the tyre pressure should be
Show answer
Correct answer: How much fuel is used per unit of energy produced
The specific consumption curve shows the fuel needed per unit of work delivered (e.g. g/kWh). Where it is lowest, the engine works most economically.
Legal reference: CZV Annex no. 2.1113
Legal references for this topic
The questions in this topic are based on these provisions:
- VRV Art. 3, 33, 34, 59b, 59c
- CZV Art. 14; Annex