Help me solve this dilemma/myth, neutral or gear?

[Mario Calero]

This question is basically for fuel economy, ever since I drive my car when it is time to make a stop I usually change to neutral and let the car roll until I need to apply gently brake and make the stop, I could stay in gear and just let off the accelerator until I need to apply brakes, Which is better for fuel economy?

Likewise, Sometimes when I run at 40,50,60 mph and I need to stop at some distance ahead, I can choose either letting the car in gear without stressing the accelerator at all or changing to neutral an IN BOTH CASES letting the car roll until it looses speed. Somewhere I read an article that claims that when a car runs at some speed ( 30,40,50 mph or above ) and then changing to neutral to save fuel is not recommended, it said it doesn’t help, on the contrary ( I don’t remember why), It said it would be better to let the car in gear and not pressing the accelerator at all, it said “when a car is running above 20mph and it is in high gears and you don’t press the accelerator at all, the fuel consumption is 0, BUT, at the same speed with the car in neutral the gas consumption is above 0, this is a common myth” What do you say folks?

Mario Calero
Managua, Nicaragua

[shepherd79]

braking in neutral will give you better gas mileage.

[Vanilla Sky]

if your car is a manual, just push the clutch in when you brake. if it's auto, leave it in gear. our auto trannies don't like being put in nuetral too much from speed.

[AZmike]

The EFI 3rg generation Accords shut off fuel flow if engine is over 1200 rpm with the throttle closed so leaving it in gear is best (infinite miles per gallon while engine braking). I'm not sure what the case is with a carb.

[Oldblueaccord]

Mario

I would not keep the clutch in, on the floor, when coasting. I think its is hard on the clutch especially the throw out bearing at speed. Putting it into neutral would be fine.

As far as the mileage I would think It could not hurt. I actually downshift to 3 then 2 nd everystop but thats just my driving style. I dont think there;s any diferance since idling really is inefficient and uses more gas than driving at slow speed.


Has you mileage improved?




wp

[Hondaisok]

I would think that the cost of wear and tear on the brakes, ie, pads, calipers, rotors, and other parts would probably offset any small gain in gas mileage gained by not using compression to stop. This may call for an expensive government subsidized study to find the truth.:)

[halxi]

I would think that the cost of wear and tear on the brakes, ie, pads, calipers, rotors, and other parts would probably offset any small gain in gas mileage gained by not using compression to stop. This may call for an expensive government subsidized study to find the truth.:)
which would you rather wear faster?
brakes, or tranny and a clutch?
in my car, i really dont care, i do an event mixture of both.
But in my dads 01 Cummins 2500 with a 5spd, i use the brakes (on flatland anyway, in the mountains is a different story), and only the brakes. Put it in neuteral, let the clutch out, and use the brakes to stop completely. Brake pads, rotors, calipers, or drums, and shoes, are a hell of alot cheaper then a clutch and/or tranny.

[speedpenguin]

I usuall engine brake until I've bottomed out the revs for the gear I'm in and then open the clutch.
I wouldn't put an auto in neutral just to brake, though.

[Hondaisok]

I was kidding about doing a study, duh, but most truck driving schools teach the students to ALWAYS use the engine to slow down, hence the "jake" brakes. I don't understand how this is hard on the transmission, clutch, etc. You would think with millions of miles and much money at stake, the trucking industry would know what saves money!

[speedpenguin]

Well, truck transmissions don't have synchronizers to wear out by constant shifting. That's why you have to double clutch when you shift a truck. Truck trannies last forever because of that.

[Hondaisok]

I respectfully disagree. A lot of drivers hardly ever use the clutch-they use the throttle to up and down shift. Of course, comparing a big rig to a car is like comparing large apples to small apples. Whatever the individual driver is comfortable with is probably ok. I prefer using the engine's compression to slow down. Cheers.

[Deadhead]

I was kidding about doing a study, duh, but most truck driving schools teach the students to ALWAYS use the engine to slow down, hence the "jake" brakes. I don't understand how this is hard on the transmission, clutch, etc. You would think with millions of miles and much money at stake, the trucking industry would know what saves money!


It's not necessarily about money as far as brakes and the transmissions go. It's about safety. Think about how fast those brakes are going to heat up slowing a fully loaded Semi-truck. Engine braking is used to slow that.

And they get that many miles out of them because they are highway miles.

[89AccordResto]

I would think that the cost of wear and tear on the brakes, ie, pads, calipers, rotors, and other parts would probably offset any small gain in gas mileage gained by not using compression to stop. This may call for an expensive government subsidized study to find the truth.:)

But it's less wear on the engine. Brake components are designed to be replaced. Engines are more of a PITA. If you use the engine to slow down the car, you're just using it more (more revolutions, more wear and tear, more gas, more everything).

Brakes on this car are cheap. $13 rotors and $50 pads. Who cares.

[speedpenguin]

My post here is pointless, please delete thx! :wave:

[MessyHonda]

well when i go on the freeway and my car is in 4th(auto) i just let go of the gas...one time i put it on 3rd gear and the engine reved up to 4000 RPM and it did slow me down but at the cost of gas... i agree with 89AccordResto breaks were ment to be replaced....what i do is just drive kinda far from the front car and when i see him braking i just let go of the gas and then press the break if it really slows down

[Hondaisok]

I surrender! I think Speedpenguin probably has the right approach. Happy 3Geeing!

[halxi]

The EFI 3rg generation Accords shut off fuel flow if engine is over 1200 rpm with the throttle closed so leaving it in gear is best (infinite miles per gallon while engine braking). I'm not sure what the case is with a carb.


no offense but i raise the :bs: to this

cold start up

my engine idles at 1700rpm, yes, high, i know. Now, if the ecu shutoff fuel, since its over 1200rpm, without me touching the throttle at that, it would die. Correct?

I think you meant to say, it only puts in the amount of fuel necessary to make the car IDLE at the set idle adjustment. Which logically, makes sense.

[AZmike]

no offense but i raise the :bs: to this

cold start up

my engine idles at 1700rpm, yes, high, i know. Now, if the ecu shutoff fuel, since its over 1200rpm, without me touching the throttle at that, it would die. Correct?

I think you meant to say, it only puts in the amount of fuel necessary to make the car IDLE at the set idle adjustment. Which logically, makes sense.

Ture.

I should have been more specific. Once the car is at operating temperature and there are no vacuum leaks that is that case though.