After purchasing my second car, my first 380, I have enjoyed it driving. I have driven almost 2k in a month!
With fuel prices soaring, to save fuel as much as possible, I shift the my automatic 380 to neutral from drive gear when I stop at red lights.
Does this help anyhow with fuel consumption and more importantly, does it harm my gearbox in any way whatsoever?

No harm at all, unless you forget, rev the engine and then engage gear. lol
Some newer cars switch off the engine when stopped, a better way to save petrol. If you really want to save petrol, don't drive it so much. lol Otherwise, just live with it.

After purchasing my second car, my first 380, I have enjoyed it driving. I have driven almost 2k in a month!
With fuel prices soaring, to save fuel as much as possible, I shift the my automatic 380 to neutral from drive gear when I stop at red lights.
Does this help anyhow with fuel consumption and more importantly, does it harm my gearbox in any way whatsoever?

It won't harm the gearbox but they don't call what you do angel gear for nothing! Its a dangerous practice as you are not in control of the vehicle in case of emergency (as neutral coasting effectively disables the accelerator and removes your ability to get out of the way instinctively) and doesn't save you any fuel.

http://www.popularmechanics.com/cars/alternative-fuel/news/coasting-in-neutral-fuel-economy

Thanks a lot for the info. I think I am better off not changing the gears..
It's so much fun to drive went on few road trips on weekend. I just started the gear shifting but as it's a safety hazards, might as well not do that.
:-P

My wife's car is a diesel Astra auto. The info display shows l/100km instantaneous fuel consumption when the car is moving. When you are stationary the display automatically changes to l/hour. When the car is stationary and in drive the gearbox automatically puts the car into neutral after a few seconds, then as soon as you take your foot off the brake or hit the throttle pedal it changes into drive...this happens so quickly it is almost not noticable. It is supposed to be a fuel saving measure. You can see it kick in and out on the l/hour display. Changing from neutral to drive makes a difference of 0.1 l/hour according to the display. Based on that I doubt doing it yourself is going to save you any money.

It won't harm the gearbox but they don't call what you do angel gear for nothing! Its a dangerous practice as you are not in control of the vehicle in case of emergency (as neutral coasting effectively disables the accelerator and removes your ability to get out of the way instinctively) and doesn't save you any fuel.

http://www.popularmechanics.com/cars/alternative-fuel/news/coasting-in-neutral-fuel-economy

That page is about coasting in neutral, not about sticking it in neutral when stopped at a red light.

I agree, coasting in neutral can be dangerous, but I don't agree there is any real danger sticking it in neutral when sat at a red light. Especially if you just missed the light and/or you know the phasing, and you know it will be a minute or three until the lights change to green your way.

I've commented on this before, why oh why do 99% of auto drivers sit at a red light for minutes on end with the car in D and their foot on the brake?

Stick it in neutral, pull the handbrake on & relax!

Especially in older cars which tend to vibrate a lot more in D with the brake on, than modern autos which are just as smooth idling in D as they are in neutral.

And stop strangling the steering wheel when stopped and going nowhere! I call these drivers 'white knucklers'. They're mainly female and they will not let go of their two handed death grip on the steering wheel no matter how long they are stopped, as though the car is some wild beast trying to buck them off.

I drive a manual not an auto, and whenever I stop and I know I won't be going anywhere soon (such as at a just missed red light) I always stick it in neutral and pull on the hand brake. I've been doing this for 40 years and nearly 1,000,000 k now and never once have I been in a situation where I needed to take emergency evasive action and regretted that I wasn't 'in gear and ready to go'. But with one proviso. If there is no-one stopped behind me I keep my foot lightly on the brake pedal so as to keep the brake lights on, to warn anyone coming up behind that I am stopped, and reduce my chances of being rear ended. But once they stop behind me I take my foot off the brake pedal.

If you apply the logic for an auto stopped at a red light of 'leave it in D with your foot on the brake so you can take off instantly if needed' across the board, that would mean that when stopped at a red light in a manual you should always be in first gear with the clutch depressed. I don't agree with that logic.

Unless of course they need to touch up their makeup :)



And stop strangling the steering wheel when stopped and going nowhere! I call these drivers 'white knucklers'. They're mainly female and they will not let go of their two handed death grip on the steering wheel no matter how long they are stopped, as though the car is some wild beast trying to buck them off.

That page is about coasting in neutral, not about sticking it in neutral when stopped at a red light.

I agree, coasting in neutral can be dangerous, but I don't agree there is any real danger sticking it in neutral when sat at a red light. Especially if you just missed the light and/or you know the phasing, and you know it will be a minute or three until the lights change to green your way.

I've commented on this before, why oh why do 99% of auto drivers sit at a red light for minutes on end with the car in D and their foot on the brake?

Stick it in neutral, pull the handbrake on & relax!

My bad! I saw shift into neutral at the lights to save fuel and thought "oh no! not a hypermiler!"

I drive a manual too and yes, handbrake in neutral is a godsend at big intersections.

I have always been under the impression that sitting in idle at the traffic lights reduces the load on the gearbox, reducing wear and tear.

I doubt switching to neutral from drive will make any noticable difference to fuel consumption. But I think it's good habit.

Thought some real numbers might help, so plugged in OBD II scanner and checked fuel flow on my car:

Idle in N (no A/C) = 1.7 l/hr with max A/C = 2.3 l/hr
Idle in D (no A/C) = 2.2 l/hr with max A/C = 2.9 l/hr

So average difference about 0.55 l/hr

At time of check my trip comp since last fill said:

Distance = 101 km, time = 5 hrs, avg speed 20.2, fuel used 24 l ie 23.8 l/100 km

:( Dreadful I know but lots of idling in ratsh1t Sydney traffic.

Lets guess 10 - 20 % idle , say 10 minutes in one hour

Then potential fuel save is 0.55l /hr * 5 hrs * 10/60 = 0.46 litre

So fuel consumption would drop to 23.54 l for 101 km = 23.3 l/100k

So I guess to put it to the "nickel plated thumb gauage" one could say it is possible to save 1 to 2 litres per tankful by using N at the lights :)

and, BTW, booked in for LPG tune on Wed am - but of course figures above refer to petrol, cos ECU doen't know its output is being converted later by LPG ECU in piggyback mode.

i always put in N when at the lights or if im parked for a little while.

i always put in N when at the lights or if im parked for a little while.

+1 . . . . only because it stops the interior mirror vibrating, in my case. lol (Does a 380 do that though?)

I also notice Sydney taxi drivers usually do it also.

They work on "shift lease" contracts and have to pay for the fuel they use.

Putting in neutral when stationary I understand would reduce transmission oil temp. Not sure about the fuel savings.

At certain lights in town I turn my car off completely, if the idle time looks like its going to be longer than a minute. I don't do this if I'm the lead car though, and if I'm a few cars back I watch the lead cars brake lights - when they take their foot off the brake I start my car and prep to go. Can take a huge dent out of your fuel consumption.

Also, I avoid using the aircon.