Slipping into neutral to slow down

[mach158]

Ok i had someone tell me today that to help slow down on the slippery roads that you can put it in neutral and it will help. I heard this once before a couple days ago and dont see how it would help at all so hoping someone can clarify this for me.

I always thought you keep it in gear and let the engine slow you down.

 

[Camaro75LT]

in an auto, it can help to go into neutral to slow down, but on ice, i like 2 use the engines revs 2 slow the car down on ice. putting the vehical in neutral will make it easyer 2 lock the tires up assuming you dont have abs. with abs, i dont think it makes a difference.

 

[night rider]

I don't know if going to neutral will help as much as some people say.

I coast alot with my auto trans, and it seems like I speed up when I throw the shifter to N, it will speed up 1-5 mph for a few sec. then start to slow down.

Also I noticed the vac readings. Cruzing along I have like 23" or so of vac, throw it in N and vac drops down to 12" or so (bigger than stock cam) Less vac would mean brakes dont work as good right?

If I need to slow down w/o useing brakes I let the engine brake for me. Down shift if needed, and just stay off the throttle

 

[Eric]

??? Something missing in that statement. By shifting a vehicle into neutral you allow the drive wheels to "free wheel" if you're not applying the brakes- which eventually, based on road/surface friction will slow you down- because there's no power going to the drive wheels at all.

However, this would be/is ineffective in accomplishing anything- applying the brakes and releasing at the first sign of slippage in a non-ABS vehicle is far more effective/speedy in slowing you down. In a rear-wheel-drive vehicle, shifting to neutral can be far worse than leaving the car in gear- ever notice when you have forward propulsion/motion and your rear end slides out that if you let off the gas the rear end will correct itself- part of this is because the effective "engine braking" has slowed the wheels down during the start of the slip/the release of the throttle to when the rear wheels regain traction. If the car were put in neutral outright- the rear wheels would be freewheeling and once they regain traction they won't "grab" the road as rapidly to a) let you know you've got traction again and should start driving appropriately for the immediate needs and b) haven't slowed the car at all, leaving you travelling at the same speed, relatively, as when you hit the traction problem, and no ability to use the throttle to "blip" the wheels to see what the actual traction situation has become (i.e. better than previous but still unacceptable or A-Ok).

Maybe on a front-wheel-drive shifting to neutral is not as consequential because the weight is over the drivewheels and the vehicle "feel" is generally impaired by all the components attached to the 2 drive wheels- meaning once you've lost any control you're basically going to slide no matter what until the car regains complete traction on those 2 wheels- so perhaps being in neutral isn't negative- but I'm not sure it's positive either.

One thing to keep in mind here is that we're talking about automobiles- not tractor-trailers with a whole lot of weight on them to slow down/pull back the vehicle. I personally would be totally adverse to shifting to neutral if I lost traction- I think it can/will cause far more problems than it will solve.

 

[zbugger]

I've never heard that one before. I have heard, and do it all the time, that downshifting helps you slow down quicker though. I remember it being called compression braking, but I could be, and usually am, wrong. Anyway, if you drive down the road, take your foot off the gas. You'll feel the car slow down. As it does that, shift into neutral. You'll be able to decide for yourself better if that really does work.

On the other hand, a vacum issue was mentioned. Load on an engine will help keep the vacum up. As you slow down in gear, the revs are kept up a bit. This actually helps increase vacum and helps your power booster. Put into neutral the revs drop down faster and allow the vacum to drop to idle levels.

Damn, I wish I could make sense.....

 

[John Wright]

The only time I ever remember shifting to "N" to get whoa'd up on a slick road was in my S-10 with the V-8. I had really low rear gears and if I let off the gas too quickly when travelling at a pretty good clip the rear tires would break loose due to the compression braking. But other than that, I wouldn't do it. I also had problems sitting at stop lights when the road was slick, the rear tires would start spinning on their own while I tried to hold the truck with the foot brake. Again this was in very, very slick conditions.

 

[punisher]

when shifting a auto into neutral while the wheel are turning doesn't that stuff up the auto box? i heard it does as the oil doesn't circulate properly?

 

[sniggle_t]

Years ago when I worked at Sears in their automotive dept. I would use this trick to get into the garage. You see, there was always a large patch of ice in front of the bay doors during the winter and if you put the car into neutral and coasted over the ice. you had a much better chance of keeping the car straight. Only time I ever needed to do this.

 

[At Home Camaro]

Just a guess, but I'd say any slight benefit of traction from coasting is outweighed by the danger of not having the car in gear if you need to "GO".

 

[camarochevy1970]

I remember a situation a couple of years ago where I had to shift into nuetral. I was going down a hill that was a solid sheet of ice. No matter what I did, unless I completely stopped the car, it kept drifitng towards the ditch, everytime I took my foot off the brake at all, it went for the ditch.

Finally I got angry, and bumped it into nuetral, and it coasted right down the hill without any more issues. As far as I can tell, the drive wheel was slipping in the ice, and pulling the car off the road.