little_rod

Hey guys, I have been driving my car and noticed that I can get 1 or 2 more miles per gallon by going into neutral like as I slow down for a light or turn, or just going downhill for a ways or I have built up a lot of speed and need to slow down a bit. I like how quiet the car gets went I put it in neutral, lol, plus I can be even more aggressive when I am accerlating without as much worry about horrible mpg.

But what I have really been wondering is if I am harming the car by having it in neutral for any length of time. My dad gave me this speech about "always keep the car in gear" and "his vechile lasted over 200,000 miles without having to replace the clutch," using his method, lol, you know how dads are.

Anyway, I just want to know if any of you guys know/think it will cause any damage or anything, I don't think it will, I mean I just brake normally and put it in gear just like I usually do. Seems to be less wear on the clutch than gearing down and such, cause I am going to get into the clutch to slow down anyway.

BTW, went from an average of 20 mpg to like 22mpg(and maybe just a little higher) using this (all around driving). So it is worth a little of my thought, heh.

Thoughts/ideas/rants????

Slareau02

I don't know about damage to the tranny but I don't really think it is the safest idea. I always keep it in gear just in case I would need to react quickly.

professor

Slareau02,

Correct and to the point!

Scott

rouxeny

I read this once in some reputable source, but I'm not sure it makes sense to me, so take it with that warning.

In neutral, the car requires gas to spin the engine at idle. In gear, when not on the gas, the RPM's may be high, but no gas is being used to actually move the pistons. This is essentially engine braking. So, while decelerating in gear, you actually consume no gas, but while in idle, you still do.

Make any sense?

little_rod

What I am concerned about is damage to the tranny. I am not talking long distances here, just short distances before a turn. It brakes just fine in neutral. If you are talking about reacting, you can brake easily. Now accerlating is a different story, but in the situations that I am talking about, I have never ever had to accerlate(sp?) to get out of trouble.

little_rod

Yeah, it makes sense, but how does that explain my sudden boost in mpg???

I left it in gear before, and now that I don't, I get better mpg. This goes against the above statement.

apsilon

I'm with Slareau02. I think it's a dangerous practice to get into. Sure you can brake but what if you need to drive around something as there's not enough distance to brake? That's happened to me several times.

If you don't believe us speak to a professional driving instructor.

The Brickyard Rat

iTrader: (1)

I can't imagine a reason why running your car in neutral would damage anything. Well, except reving the engine to high but thats not what your talking about.

bellox

Not to me. When the engine is forced to a higher rpm, the idle fuel rate has to richen (more gas than idle) to prevent a lean condition. An example is carbs have richening valves that open to increase fuel when the engine rpm is high when the throttle is idle.

So, coasting in neutral is better for MPG but can leave you hanging in a defensive situation without any manuvering accel.

I just realized this is OT.

little_rod

Hmmm, so what most of you guys are pointing out is it is a safety hazard as far as driving is concerned. I see your point, and agree with this, cause it is more safe to be in a gear at all times to avoid other idiots on the road.

I guess the main thing I am looking for is if it is harming the drivetrain of my car to do it. Point taken that I am living dangerously by doing it driving safely wise, but does it harm my car to do it??? Cause, I am saving gas (bout 2 mpg), and that is a solid fact that I can see.

Guess I am living on the wild side, who is up for nitro and twin turbos...............

joust75

iTrader: (1)

I am sure gas is used during engine breaking. You still hear detonation when you downshift dont you? You use gas when you engine break. Less than when under load but you are still using gas! In fact I remember reading that downshifting is BAD for fuel economy.


Nothing hurtful about cruising in neutral. Just dont ever ride the clutch.
Also if you blip the throttle and match the revs when you do put it back into gear, you are further saving the clutch!

jeffw

My motorcycle transmission will overheat if it doesn't stay in gear. When it's in neutral it does not cool properly in the oil unless everything is spinning.

I don't know either way about the 350Z, but I'd find out for sure before riding in neutral a lot.

--
Jeff

Trackbite

little_rod,
I have always driven my cars by going into neutral while slowing to a stop. I typically don't do it while going down hill though. I have never had any problems. I actually got into the practice after paying a huge repair bill on my 6sp Z28. I had worn the clutch down to where the clutch pedal stuck to the floor. My bad of course. I should have taken it in sooner. Anyway, I started doing it to lessen the wear on the clutch and motor. There is less friction wear on the clutch and no enigne brake. I'll le the Brembos stop the car I'm so used to putting it into neutral that I can quickly go straight into gear if I have to.

tsixr

Why is it so bad to ride the clutch?

professor

If you are driving around with your foot on the clutch pedal, then you wearing out the throw-out bearing (release bearing)
It is not designed to run every mile the car is driven.

Slipping the clutch is going to shorten the life of the clutch big time. One of the worst offensives is holding the car on a hill at a traffic light waiting for the green. Might as well light dollar bills on fire.

Scott

stealthrapt0r

i don't think theres anything wrong with riding in netural, i've been doing taht in my civic for over 30k miles and i get 32-34 mpg for city driving

synergytheory

Auto or manual?
If manual, you can engage the clutch and still down shift without releasing the clutch, keeps you out of danger and keps the mpgs down. I do this and when I'm not doing that I am heal and toe rev matching

frenzee

iTrader: (1)

Don't mean to be harsh my friend, but that's about the worst thing you could do to any clutch - It's called riding the clutch.

synergytheory

I thought we were talking mpg here? Fair enough I guess you are right, but I personally have never had to change a throwout bearing.
BUT normally down shift through the gears, and ever since I got the hang of heal toe my mpg went up, so I tried to combat that problem with a bad thing.

Can anyone confirm the theory that downshifting doesn't use gas? I don't see how it could be possible, 'coz the pistons pushing harder is going to inturn suck more air through the intake port, which will also suck more gas through?

apsilon

Of course it uses fuel. Anytime the engine is running it uses fuel. It may not be a lot of fuel but it does consume some.