Does Coasting in Neutral Save Fuel?

[McAlexandra]

Coasting in neutral does not save fuel and can sometimes even consume more fuel, primarily due to the working mechanism of fuel-injected engines. Fuel-injected engines determine the amount of fuel injection based on computer programming. When the car is in gear and the driver releases the accelerator, the computer puts the vehicle into coasting mode, during which the engine does not inject fuel for a significant period. However, if neutral is selected, the computer switches the vehicle to idle mode, and the engine continues to inject fuel. This is why coasting in neutral can sometimes use more fuel. Additional Information: 1. When a vehicle is coasting in neutral, the connection between the engine and the drive wheels is lost. The car moves forward by its own inertia, and the engine can no longer provide resistance to the drive wheels. In such a situation, if an emergency occurs, the entire braking force must be provided by the brakes alone. However, the braking force that the brakes can provide is limited, leading to longer stopping distances and an increased risk of accidents. 2. For older car models, coasting in neutral could indeed save some fuel, which led many drivers to develop a habit of shifting to neutral whenever possible. However, nowadays, fuel-injected engine models have become mainstream in the market. Therefore, the answer to whether coasting in neutral saves fuel is clear: it does not save fuel and can sometimes consume more, in addition to being detrimental to driving safety.

[SanMicah]

I've been driving for over 30 years and have deep personal experience with coasting in neutral. In earlier years when driving older manual transmission cars like the Santana, coasting in neutral did save some fuel because carburetor-era engines consumed less fuel at low speeds. But modern cars are completely different - they all use electronic fuel injection systems. When coasting in gear, the ECU automatically cuts or reduces fuel injection, whereas in neutral it has to maintain idle speed by injecting fuel, actually consuming more. I've tested this with an onboard computer - coasting in gear saves about 0.5L per 100km on the same route. More importantly, there's the safety aspect. Coasting downhill in neutral removes engine braking, making it easier to lose control on steep slopes or during emergency braking. I've witnessed several accidents caused by this. Saving a little fuel isn't worth compromising safety - I recommend developing the habit of coasting in gear.

[FaithLynn]

As someone who drives to work every day, I once specifically researched whether coasting in neutral saves fuel. From practical driving experience, modern automatic or electronically controlled manual transmissions actually consume less fuel when coasting in gear, as the engine can intelligently cut off fuel injection. For example, when driving my Honda Fit, the dashboard displays instant fuel consumption. When coasting in gear, the number drops to 0, whereas in neutral it maintains an idle consumption of 2-3 liters per hour. This is due to technological advancements, unlike older cars where it was simpler. Whether it saves fuel also depends on road conditions - on flat straight roads the difference might be minimal, but downhill in mountainous areas the risks are higher. My neighbor once lost control and hit a tree while coasting in neutral on a curve, and the repair costs were ten times more than the fuel saved. All things considered, developing the habit of coasting in gear is the smarter choice.

[OwenMarie]

I used to think coasting in neutral saved fuel, but my driving instructor corrected me during lessons. Modern car engines automatically cut off fuel injection when coasting in gear, achieving zero-fuel idle, whereas in neutral, the engine must maintain minimum idle fuel injection to avoid stalling. This is especially noticeable when driving small-displacement cars in the city—the real-time fuel consumption display shows that coasting in gear is more economical than in neutral. Safety-wise, coasting in gear enhances braking effectiveness with engine braking, while coasting in neutral increases stopping distance, raising the risk of rear-end collisions. Don’t underestimate this difference—it could be life-saving at high speeds. Peace of mind beats fuel savings; adopt this new driving habit.