Saving gas in neutral?

Drewet88 · #1 05-01-2006, 04:26 AM

I dont know if this is the right thread....

I just heard from a friend that you could save gas if you get up to cruising speed and switch into neutral and just coast. Then when you start losing speed he switches into 1 (I really dont know what any of the number are for besideds drive and overdrive I dont know what 1 or 2 are for) and drives with that.

Sounds like it would work but I just wanted your opinion on it?

curtis73 · #2 05-01-2006, 05:20 AM

In a word, no. It takes a certain amount of energy to maintain speed, a certain amount to accelerate, and a certain amount just to idle. If you drive normally, you are expending energy maintaining speed. If you do what your friend suggests, you expend energy getting up to speed, waste that energy by letting it coast, then expend energy again getting back up to speed. Not to mention; alterations in speed are the single largest contributor to highway deaths; second only to alcohol. Keep a steady speed, save gas, save lives. Period.

PlayStation3 · #3 05-01-2006, 09:56 PM

using cruise control would help it basicaly by what curtis has said

Drewet88 · #4 05-02-2006, 01:19 AM

Thanks. I never actually tried it because my car is out of comission and now I'm not going to try it.

So what are the other gears for on an automatic transmission do any of them help you use less gas?

curtis73 · #5 05-02-2006, 06:49 AM

Nope. Put it in the highest gear, use a light right foot, avoid rapid changes in accelerator position, and slow down a few mph.

fredjacksonsan · #6 05-03-2006, 09:10 AM

The only place I can think that will work is in mountainous terrain, where you might be able to coast downhill for awhile.

(However may not be a good idea on twisty roads or extremely steep descents, where you would want to maintain some engine braking)

phantomcobra · #7 05-04-2006, 01:22 PM

Actually the gear selection you are using now is the best "p" !!!

fredjacksonsan · #8 05-04-2006, 01:35 PM

Quote:

Originally Posted by phantomcobra

Actually the gear selection you are using now is the best "p" !!!

How true.

turtlecrxsi · #9 05-04-2006, 03:47 PM

I live in a mountainous/hilly area and I take it out of gear (manual) all the time to coast down substantial hills. Actually, I've passed cars in neutral in some areas where people doing the slow and steady and going absolutely nowhere fast. Timing is everything though. As Curtis stated, expending energy to get up to speed is worse. So I try to stay smooth and not coast real fast only to hit red lights etc. Honestly though, I've noticed a gain of a few mpg...

Cmdridq · #10 05-07-2006, 06:19 AM

Driving around with the trans in neutral is illegal in most states. Also, using your cruise control works well on flat terrain but if you going up and down a lot of hills you are better off not using it.

jveik · #11 05-07-2006, 01:36 PM

i have seen posts here that say if you have an automatic transmission, that it is bad for the tranny to be in neutral when you are going at somewhat high speeds, due to lubrication issues or something. i have no idea how the tranny is lubricated or why you need to be in gear, but thats what the post said. i dunno if it also has anything to do with manual trannies or not

curtis73 · #12 05-07-2006, 01:51 PM

Jveik's right. Automatic trannys are designed to be operated in gear. The oil pump is driven directly from the engine and your pump's output is proportional to RPM. Putting the car in neutral lets RPMs drop to idle, so the pump is supplying the minimum lube for the moving parts of the tranny, but the tranny is spinning at 70 mph. Some trannys are fine that way, others will overheat or cause other damage.

Manuals are not as sensitive to it since they are simply bathed in oil. Since you're still turning some of the gears in neutral it still wraps lube up around the gears.

UncleBob · #13 05-08-2006, 12:18 AM

on decel most modern EFI systems shut off the injectors, so there is no fuel wasted. If you are on a steep hill and decelling in top gear maintains the speed you seak, then you will use less fuel leaving it in top gear and deceling, than you would putting it in neutral and coasting down the hill.

I agree with the above advice. Do not put it in neutral with an automatic. Saving 10 cents worth of gas isn't worth a $2000 tranny rebuild.

Drewet88 · #14 05-08-2006, 01:46 AM

Is it bad to put it in neutral when you're at a stop light?

Chiquae07 · #15 05-08-2006, 03:48 PM

stop light no....while moving....yes. ive been doing this for abiout a year now. everything is fine. just made sure to keep it in gear on hikllks..

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