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Difficulty: MediumCoasting and Engine Braking

In modern fuel-injected vehicles, coasting in neutral consumes less fuel than remaining in gear with the accelerator pedal released.

Answer: Answer

Answer

False
The statement is false because modern vehicles equipped with electronic fuel injection cut off fuel delivery entirely when the accelerator is released while remaining in gear. Conversely, coasting in neutral disengages the engine, forcing the engine management system to inject fuel continuously to prevent the engine from stalling.

Step-by-Step Solution

1
Analyze fuel delivery behavior in modern fuel-injected vehicles during overrun.
When a driver releases the accelerator while the vehicle remains in gear, the road wheels drive the engine and the engine control unit (ECU) cuts fuel injection to zero.
Modern vehicles employ deceleration fuel cut-off technology to maximize efficiency and provide engine braking.
2
Analyze fuel delivery behavior while coasting in neutral or holding the clutch down.
Because the engine is disconnected from the wheels, the ECU must continuously inject fuel to keep the engine turning at idle speed (typically 700–900 RPM).
The engine cannot rely on vehicle momentum to stay running when disengaged from the drivetrain.
3
Compare the relative fuel consumption of both techniques.
Remaining in gear with the accelerator released uses zero fuel on overrun, whereas coasting in neutral burns fuel at the idle rate, making the statement false.
Direct evaluation of the comparative fuel consumption assertion.

Key Concept

Engine overrun fuel cut-off versus idling fuel consumption during coasting
Estimated Time:45s
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Topics

Coasting and Engine Braking

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