Describe what power limited and traction limited acceleratio

Describe what power limited and traction limited acceleration mean. Which of these are more prominent in passenger cars?

Solution

Acceleration Performance :

As power delivered to the wheels increases, acceleration eventually becomes limited either power or traction.

In power limited acceleration, the vehicle reaches its peak acceleration because the engine cannot deliver any more power. Assuming adequate power from the engine, the acceleration is limited by the coefficient of performance between the tyre and road.

In traction limited acceleration, the engine can and does deliver more power, but vehicle acceleration is limited because the tires cannot transmit any more driving force to the ground.

Equation gives the maximum transmittable force: F_x = u F_z

where µ is the coefficient of friction between the tire and the road. Note that µ depends on many factors, including load and velocity. If F_x exceeds this limit, the tire slips excessively and enters dynamic friction, where the coefficient of friction dramatically decreases, i.e., it breaks traction.

Power limited acceleration is more prominent in passenger cars.