Thursday, August 5, 2010

Coasting in neutral won't help any person

Don't coast when in neutral because it won't help

It is common for people to want to know what driving techniques will conserve them money in gas. Despite the fact that some products claim to help with fuel cost reduction, numerous of them are doubted. Hypermiling is one thing that is scientific. However, one driving technique that some associate with fuel economy – coasting in neutral as the engine is idling – has little to do with effective hypermiling, reports Popular Mechanics. It is also very dangerous to do.

Accelerator doesn’t work when in neutral

If drivers experience road hazards while coasting in neutral, they cannot use the accelerator pedal to keep away from the danger. Being in neutral also prevents you from getting around sharp corners. This happens when the engine no longer correlates with the drive train.

The saving gas argument?

It doesn’t make any sense that gas can be saved when in neutral. In terms of gallons of gas consumed per hour, Popular Mechanics states that one gallon is consumed per hour when a car engine is left idling. Considering that, going down a hill that is a mile long at 30 mph will be about .033 gallons used.

What about the rpm still going on

From idle to full throttle, an oscilloscope shows the pulse-width-modulated wave signal to be between 5 and 8 percent. More fuel is used with more rpm which goes up with percentage. 1,000 rpm is what the idle rpm is. This varies somewhat by vehicle. At that point, the car’s fuel injection starts adding fuel to keep the engine from stalling out. The driver feels this as a slight rev up, and also the oscilloscope shows that pulse increase. As outlined by Popular Mechanics, this shows that really, gas is just being used when it doesn’t have to be.

The trip computer getting tricked

When a car is in neutral, the trip computer sees something different than what is happening. Increased mileage which is a “false positive” is shown to your computer. Your odometer and gallons of fuel you put as part of your tank are going to be a better indicator of how numerous mpg you get anyway. 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



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