Does Putting a Manual Transmission in Neutral Save Fuel?
3 Answers
Nowadays, coasting in neutral with a manual transmission does not save fuel. Introduction to Coasting in Neutral with Manual Transmission: So-called coasting in neutral refers to the driving behavior where the manual transmission vehicle is shifted into neutral during driving, allowing the vehicle to move forward by inertia. When the car is in neutral, the clutch disconnects the engine from the power system, and the engine can only maintain an idle state without power output. Fuel-Saving Tips for Cars: Dirty spark plugs and clogged air filters can reduce fuel efficiency. Maintain proper tire pressure. If the tire pressure is too low, it will consume more fuel, so check the tire pressure frequently. Avoid prolonged idling. The engine still consumes fuel when idling, so try to turn off the engine when parked and waiting.
I used to think about this a lot when driving manual transmission cars. Coasting in neutral did save a bit of fuel, but that was only true for carburetor-equipped cars twenty years ago. Modern fuel-injected vehicles are completely different - the ECU automatically cuts fuel supply during engine braking (gears engaged), with the injectors not releasing a single drop, making it actually more fuel-efficient. If you shift to neutral, the engine still consumes fuel to maintain idle. But remember, never coast in neutral downhill - last time I tried it on a mountain road, losing engine braking made my brake pads smoke, and I had to quickly downshift in panic.
This question needs to be broken down. In city driving with a manual transmission, shifting to neutral and pulling the handbrake at long red lights is indeed more comfortable than holding the clutch and can save some idle fuel consumption. However, don't follow the old habit of coasting in neutral on highways—it's not only non-fuel-saving but also dangerous. Modern engine management systems cut off fuel supply when you release the throttle in gear. Additionally, prolonged coasting in neutral can cause abnormal temperature rises in the transmission oil, and I've seen several cases of synchronizers failing prematurely. The most intuitive way is to check the real-time fuel consumption display—showing 0L/100km while coasting in gear means real fuel savings.