Does switching from drive to neutral save gas?

Question

ive gotten into the habit of doing such while im driving down a hill or a long stretch of road and i feel like i have enough momentum to cruise. if i start to slow down too much, i switch back to drive. is this ok or can it damage my engine? and if it is ok, can it also save gas? i drive an automatic 2004 chevrolet aveo if that helps?

Answer 1

The difference would be minimal as you're coasting when going down a hill and not placing a load on the engine.  The engine at that point is just  giving the cylinders enough gas to keep the car running.  

As already suggested above, if you've already gotten into this habit, you should be able to tell if this works or not.  Just record your mileage driven and fuel quantity every time you fill up to get a running average of the difference.

EDIT:  In response to the first post.  What you're doing is commonly referred to as "riding the clutch" and it is very hard on the the clutch and will shorten its lifespan considerably.  I suggest you stop that practise.

Answer 2

Coasting down hill in neutral might save gas, but you'll be replacing brake pads sooner.  You lose engine braking while in neutral.

Also, every time you shift into drive, you pump a little extra gas (about 1/2 oz) into the manifold (or cylinders) to compensate for a lean mixture when you open the throttle suddenly.

As one suggested, drive the same road several times using both methods and tell us what your results are.

Answer 3

That's a habit you need to stop. In most states putting your car in neutral while in motion is illegal, but first they have to catch you doing it. Switching to neutral won't save much gas. It won't hurt the engine but it will shorten the life of your automatic transaxle. ...so if you really are saving anything on gas it won't be enough to pay for a $2200 new in the crate automatic transaxle. Yes, that's a real figure. You can check it yourself if you want: http://www.gmpartsdistributor.com/partlo...

Answer 4

David L is right, so bad for your car.

Answer 5

my x  told my mom it does, and now every red light she stops on, she will put d car on neutral.

now idk if it works, and if it does, is it worth it to look all dumm while switching gears when ur car is an automatic?

cuz if it does, even i will rather look weird haha

Answer 6

maybe but you would have less control of the vehicle particularly if it is a steep and/or winding road, gears are always a good way of slowing a vehicle and sometimes this cannot be done easily if you are gliding.   i would think you could have more wear and tear on brakes for slowing.    it is often recommended to use lower gears for descents than brakes for this reason.    i would suggest you stop this practice.    is an accident less cost than a possible accident and the resulting trauma and damage to self and car.

Answer 7

i wouldnt know... but im not gonna lie when i go down hills i always push my clutch in... lol

Answer 8

Why don't you tell us?  If you've been doing it a while, you should have experienced the savings yourself.  If you can't tell any difference, then you can't tell any difference.

In some situations, it wastes gas to put a car in neutral.  If you going down a steep hill, then gravity is driving all your accessories.  That could actually be good.  The computer can shut the gas all the way off if it is designed to.  I've had some cars that did that - you could feel it.

But anyway, never argue in the presence of data.  Take the data yourself, and tell us.  You'll be a hero.

Answer 9

it will save you gas, definitely. an AT car goes into some degree of engine brake when your foot isn't on the pedal. however, switching from drive to neutral often can damage your transmission, not your engine. the idea behind AT is that you're in "Drive" for as long as you're still driving... you're not supposed to change it until you've parked your car at your destination.

also, it's not a good defensive driving technique to be in neutral with the car moving, because if ever you need to suddenly slow down, staying in gear helps the brakes slow down and break the car's forward momentum.

you already own a fuel-miser of a car, so i suppose it wouldn't hurt you too much if you just stayed on drive. =P

Answer 10

I used to do that downhill, until my differential went out (Big Time) when I e-a-s-e-d back in to drive.

Then I quit that nonsense!