It is common for people to want to know what driving techniques will save them money in gas. Although you will find products around that will allegedly help with this, a lot of that isn’t accurate. Driving techniques like hypermiling have grounding in scientific fact. Popular Mechanics reports that coasting in neutral won’t do anything close to what effective hypermiling is going to do for you. It is also very dangerous to do.
Coasting in neutral disables the accelerator
If drivers experience road hazards when coasting in neutral, they cannot use the accelerator pedal to stay away from the danger. It is also nearly difficult to get around sharp corners when in neutral. The engine and drive train aren’t connected anymore.
Trying to conserve gas?
It is an illogical claim that a car experiences greater fuel economy while coasting in neutral. Every hour you leave your car running, one gallon of gas is used in it. You will use .033 gallons of gas just being in neutral down a mile hill at 30 mph.
But the engine is still producing rpm
From idle to full throttle, an oscilloscope shows the pulse-width-modulated wave signal to be between 5 and 8 percent. The higher the percentage, the higher the rpm goes, and more fuel is consumed. Ultimately, once the car reaches the bottom of a hill – or as a car creeps up to a traffic light – the engine eventually slows to an idle rpm, about 1,000 rpm. Of course your automobile may be just a little different. The car will only continue to run then as the fuel injection system puts in fuel. The driver feels a rev up at the exact same moment a pulse increases on the oscilloscope. Thus, gas is actually being wasted when the car shifts into neutral, claims Popular Mechanics.
Tricking the trip computer
For a variety of reasons, when a car is coasting in neutral, inaccurate readings are being sent to the trip computer. Essentially, the computer sends a “false positive” of drastically increased mileage while coasting. When you analyze fuel economy, it can be better to take a look at the gallons in tank up against your odometer. Popular Mechanics reports you feel safer when turning off a car at a light instead of sitting in neutral.
Further reading
Popular Mechanics
popularmechanics.com/cars/how-to/repair/coasting-in-neutral-fuel-economy
A “gravity hill” in Chenju, South Korea
youtube.com/watch?v=yBXjwnc51Pc
