Why Is Coasting While Driving Dangerous and Illegal?

There are plenty of driving techniques that you can use to save gas. For example, drafting behind a large truck to improve your car’s aerodynamics – since the truck is blocking the wind – is one of them. That’s actually pretty dangerous, but so is coasting. But why is coasting while driving dangerous and, in some states, illegal?

What is coasting?

A man drives a 2011 Volkswagen EOS.
A man drives a 2011 Volkswagen EOS. | Getty Images

Coasting is when you put your car in “neutral” or depress the clutch when going downhill. Most of the time, this driving technique is used to save fuel as the thought is that the engine is idling and therefore using less fuel. However, Jason Fenske from Engineering Explained demonstrated in a video that it’s better to use “engine braking,” which is when you leave a car in gear when going downhill instead of shifting it into neutral.

Engine braking is solely reserved for cars equipped with manual transmissions. Cars with automatic transmissions have computers that do this automatically for the best efficiency.

Why is coasting dangerous?

Coasting your car in neutral while going downhill can be dangerous because you don’t have the optimal control of the car’s throttle. While coasting, the car’s drivetrain is disconnected from the engine, making engine braking impossible.

Also, the car can speed up exponentially when coasting down a hill in neutral, which can be unsafe in populated or suburban areas. If you need to re-engage or shift into gear to regain control of the car quickly, you will have less time to do so.

Coasting is illegal in some states

The Mazda Miata manual shifter in neutral.
A leather wrapped 6-speed manual transmission gear shifter on the 2017 Mazda MX-5 Miata Retractable Fastback edition. | Staff photo by Christopher Evans

Certain U.S. states like California, Michigan, Illinois, Georgia, Nevada, Nebraska, Montana, Tenessee, and Washington all have rules regarding “no coasting on a downgrade,” according to a list on Skeptics. However, plenty of other states do not have such rules.

If you were to get into an accident or get caught coasting in neutral when going downhill, you could receive a fine. In some states, like California, that fine can cost up to $238. That’s a lot to pay for just for driving in neutral.

Engine braking your car is far better

As stated before, if you find yourself stuck in the nasty habit of coasting when driving downhill, you may want to start engine braking instead. In order engine brake a car, you can leave it in a lower gear and depress the clutch. Doing so will cause the engine RPMs to climb, making the car noisy. However, the car’s injectors will shut off when doing this, which will allow you to save gas.

Coasting while driving might seem the most innocuous way to cause an accident or even get a ticket, but it’s still potentially dangerous. Gas is pretty expensive nowadays, so many drivers are doing what they can to pay less at the pump. However, coasting isn’t a great way to go about it. Here are 5 tips to save money on gas no matter what kind of car you drive.

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