Lesson 6 of 12 · Automotive basics

Checkpoint: from engine to road

3 min50 XP3 questions

Can you explain one drive path using three different quantities without treating them as the same thing?

Bring the first five ideas together. Read each prompt carefully; you can study the explanation and retry whenever an answer needs work.

The idea

Torque is turning effect, RPM is rotational speed and power is the rate of doing work. The transmission connects their speed-and-torque relationship to the drive path.

Think it through

Say the path from engine to driven wheels. Then place an ideal 3:1 reduction in it: if input speed is 3,000 RPM, what is output speed and what happens to torque?

Show the reasoning

Engine → transmission → differential → driven wheels. In the ideal 3:1 reduction, speed becomes 1,000 RPM and torque triples. The ratio changes speed and torque together.

Take away
  • Give each quantity its own meaning and unit.
  • Check speed and torque together after a ratio change.
Sources