Why is coasting in neutral illegal

For my automatic, coasting in D with no throttle input is around rpm on the engine, whereas coasting in neutral is rpm. For manual, how would shifting from neutral to top gear cause damages compared to shifting from 4th to 5th? The issue is that when the vehicle is coasting in neutral it needs to use fuel to keep the engine ticking over and avoid stalling. Not an issue while coasting, but a big issue when you want to start going back up a hill as it will need the starter motor to restart the engine, and this at the same time as someone trying to re-engage the transmission….

This allows the engineers to cut fuel completely when the vehicle detects this. Zero fuel use. Starting on up that next hill only requires the engine to reintroduce fuel. Many modern cars except like…. Mondeo diesel. Leaving it in gear uses way more than popping it into neutral.

Even its instant sous consumption gauge confirms the usage difference off-throttle vs neutral. Even if it saves fuel, what is the real saving dollar terms? I suppose it depends on the opportunities to coast. Any real saving would require the ignition to be turned off. I did that in my XW Falcon once or twice. The Instant Fuel Use gauge drops to zero when coasting down a hill. Shift to nuetral and the injectors turn back on the keep the engine idling … and the display shows fuel usage.

The car coasting down hill has to spin the engine at a minimum rpm before the injectors turn off. As you are going faster, you have to use your mechanical brakes more aggressively, which can wear out brakes more quickly. While it is not illegal to coast downhill, if you get into an accident and you are deemed not to be fully in control of your vehicle, you would have committed an offence.

With the engine engaged, these devices reduce fuel use when the accelerator is not depressed - e. But what if you are coasting in neutral, going down a hill? This disconnects the engine from the wheels which, with your foot off the accelerator, means the car cannot get the rotational power it needs from the wheel. In this case, it uses a small amount of fuel to keep engine powered - essentially "idling" - rather than drawing the necessary power from the wheels.

While with older cars and classic cars coasting could save a small amount of fuel, with modern ECUs this technique does not work. But whether you have an older or a newer car, coasting is potentially dangerous and should be avoided. The computer is always going to maximize fuel consumption and emission levels. Mechanical: Drivers run the risk of having mechanical issues if they shift incorrectly or over-rev the engine. What if the vehicle stalls?

Will the driver find the right gear or put it in reverse? These are all risks. In my travels lately, I have noticed yet another disturbing trend: drivers flicking cigarette ashes out their windows. Active Oldest Votes. Alabama The Code of Alabama has only a no-coasting on a downgrade law A Alaska Alaska Statutes don't have any laws regarding being in neutral.

Arizona Section of the Arizona Statutes is the only mention of "neutral" in the Transportation title, and it's a no-coasting on a downgrade law. Arkansas Arkansas has a no-coasting on a downgrade law: A. Searching through the California statutes for the terms "neutral" or "gear" did not return any relevant statutes, only a no-coasting rule at Section The driver of a motor vehicle when traveling on down grade upon any highway shall not coast with the gears of such vehicle in neutral.

Colorado Colorado only has a no-coasting on a downgrade law: C. Florida Florida statutes make no mention of the word "neutral". It does have a no-coasting on a downgrade rule, though: Sec.

Michigan The Michigan Vehicle Code only has a no-coasting on a downgrade statute. Minnesota Mississippi Missouri Montana Montana code only has a no-coasting on a downgrade law: The code does not mention anything about coasting while approaching a red light. North Dakota Ohio Ohio statutes don't have such a rule. Pennsylvania Pennsylvania Statutes Title 75 Vehicles doesn't mention such a rule.

South Carolina South Dakota Tennessee Tennessee Code Annotated has a no-coasting rule either in neutral or clutch disengaged, but no rule regarding a vehicle stopped at an intersection. Texas Texas Statutes Transportation Code Title 7 Chapter has a no coasting rule at section An operator moving on a downgrade may not coast with the gears or transmission of the vehicle in neutral.

It doesn't have any rule about being in neutral approaching a red light. Washington Washington only has a no-coasting on a downgrade rule at Section West Virginia West Virginia statutes don't have any laws about being in neutral. Wisconsin Wisconsin statutes don't have any laws about being in neutral. Wyoming District of Columbia.

Improve this answer. I'm slightly off-topic here: isn't the sole purpose of no-coasting laws to allow people to maintain speed while downshifting? If so, aren't these no-coasting rules outdated now since the large majority of cars in the US have an automatic transmission with no possibility to downshift excluding sequential gear boxes?

When going downhill, a coasting car is more difficult to handle in case of a brake failure. JohnC although I think the danger is slightly overstated, this site quotes the UK's highway code, which apparently states: "Do not coast, whatever the driving conditions.