Does Coasting in Neutral Save Fuel in a Manual Transmission?

[VanEmerson]

Coasting in neutral with a manual transmission does not necessarily save fuel and may even increase fuel consumption. Many modern vehicles are equipped with electronically controlled fuel injection systems. When the car is shifted into neutral, the Engine Control Unit (ECU) defaults to an idle state, increasing fuel injection to maintain idle speed. The electronic fuel injection control system inherently has fuel reduction or cut-off functions. Utilizing neutral coasting in such scenarios not only negates these functions but also increases fuel injection. The potential damages of coasting in neutral with a manual transmission include: 1. Causing jerking sensations; 2. Reduced braking efficiency; 3. Negative impact on engine lifespan; 4. Increased risk of transmission gear breakage.

[McJuliet]

I've been driving manual transmission cars for over 30 years. Back then, old drivers taught me that coasting in neutral could save some fuel, but I later realized that was a misconception. Modern car engines are electronically fuel-injected. When coasting in gear, the wheels turn the engine and the system automatically cuts off fuel injection, using almost no fuel. In neutral, however, the engine has to maintain idle speed, continuously consuming fuel to keep the RPM. From a safety perspective, coasting in neutral is also dangerous as you lose engine braking and rely solely on the brakes to slow down. In emergency turns or sudden situations, the slower response time can easily lead to accidents. When driving, I always make it a habit to coast in gear - it's more fuel-efficient, stable, and protects the brake pads' lifespan. I've seen many friends coast in neutral only to find their fuel consumption data actually increases. Don't be misled by traditional thinking; always check the manual or consult professional mechanics.

[DelArianna]

As a new driver who just got my license a few years ago, I initially wondered if coasting in neutral was a fuel-saving trick. After trying it a few times and checking some car forums, I found the reality was quite disappointing. Modern manual transmission cars cleverly cut off fuel supply when coasting in gear, relying on the vehicle's momentum to keep running; coasting in neutral, however, keeps the engine idling, wasting fuel. My little old car recorded fuel consumption a few times, and coasting in gear saved about one liter per 100 kilometers. It's also less safe—I almost rear-ended someone once because of the reduced engine braking. I recommend practicing coasting in gear more often—it's both eco-friendly and cost-effective. Don't make the same mistakes I did.

[Espírito Santo]

From a technical perspective, coasting in neutral does not save fuel. Modern manual transmission engines can cut off fuel injection when coasting in gear, resulting in zero fuel consumption. However, in neutral, the engine must maintain idle speed, which continuously consumes fuel. Additionally, coasting in neutral increases brake wear and may shorten component lifespan with prolonged use. It is recommended to check the vehicle's computer data and utilize coasting in gear more frequently to improve efficiency.