Whats better for gas? engine braking, or coasting in neutral?

[shenanigans]

the car does know when the clutch pedal is being pushed. I had an issue with the switch that signals the computer that recently and showed up as a wierd code through hptuners(not a SES) and prevented my cruise control from working.


go out, enginebrake, shut car off then turn back on, you will see.

Makes sense the compression of the motor is what is slowing you down, the motor is spinning plenty as well, because the power steering works just fine as well.


at low speeds you will have issues, but wen the car is moving and has that much inertia you don't notice it as much.

[FunkZ]

Ah, so you're saying this is only when decelerating above 2000rpm? Weird, you would think this would be more noticible then... as you coasted down to 2000rpm suddenly the amount of engine braking would decrease?

[shenanigans]

Originally posted by FunkZ:
Ah, so you're saying this is only when decelerating above 2000rpm? Weird, you would think this would be more noticible then... as you coasted down to 2000rpm suddenly the amount of engine braking would decrease?

It sort of does... I just thought it was do to less revolutions against the force of engine compression.

[SpeedingFirebird]

Originally posted by victimizati0n:
lower RPMs=less gas

This is not always true. I debated this with someone else before - this generalization does not always hold.

Going up a steep hill - 5th gear full throttle low RPMS or 3rd gear 1/4 throttle 4K RPMS. Which uses more gas? Lower RPMS=MORE gas. This is using my instant fuel consumption gauge on my bimmer.

[Publican]

Firstly, if you have to coast in neutral to save gas in a V6, maybe you should buy a bicycle.

Secondly, coasting in neutral is idiocy - you have no control whatsoever in case of an emergency except brakes - which going down a long hill may easily fail if you have been riding them due to being in neutral in the first place.

Gear down and spend the 7 cents you might save by freewheeling.

[PalmHarborBlkv6]

Want to save gas? Here is a trick I learned from European Taxi
Drivers that use gasoline powered Taxies.....when you come to a stop light you know is a long light........turn off the engine. You are burning fuel for no good reason. Also when waiting for someone in a parking lot, air port pick up lane...turn it off.
If you are afraid the car won't start again...then you should
get the battery replaced....$30 a Walmart.

[SilverBirdSeven]

Europeans :rolleyes:
Not only would that not save gas, it would use more. It takes more gas to start an engine than it does to sit idle for quite a while.

[slow6]

Acetone

[cam98aro]

Originally posted by FunkZ:
</font><blockquote>quote:</font><hr />Originally posted by 98Camaro3.8:
All the injectors are disabled. You will use no gas during engine braking.

If there is no gas feeding the cylinders, then in theory you could turn the key off entirely while coasting to a stop in gear and it would have the same effect? I can't see how that's correct. If forward momentum alone was the only thing turning over the motor you would not "coast" to a stop, you'd come to a screeching halt.


</font>[/QUOTE]are you joking??

the back tires are PUSHING the engine, shutting the engine off isnt going to do anything, it is going to do the same exact thing.

It seems liek your thinking once an engine is off, it is locked up or something.

[cam98aro]

Originally posted by SilverBirdSeven:
Europeans :rolleyes:
Not only would that not save gas, it would use more. It takes more gas to start an engine than it does to sit idle for quite a while.

[img]graemlins/slap.gif[/img]

lol it doesnt use more gas to start it... maby only if the car is carburated

[SilverBirdSeven]

... wow. I'm not even gonna argue about it

[Turbo V6 Camaro]

M5 best is put the car in N and let the clutch out.. this lets the motor just idle ( i know from my vac and WBO2 ) i have tried both way and holding the clutch or putting the tranny out of gear give better gas milage then down shifting

with the the Auto.. the WBO2 goes to 18:1 (basicaly pure air) the vac goes to -20 sometimes -25 untill about 2500 rpms (my stall changes it some) and then the motor idles normal again

less rpm DOES NOT MEAN less fuel.... it all in the load.... higher load = more air and fuel needed to do the same amount of work.

bogging the car in every shift can make you have worse gas milage, i tested this to

for those with a turbo you can prove this to yourself i can pull 1-2 psi in 4th gear under lock up at only 1500-1800 rpm

in thrid at the same rpm i have -8 to -5 vac

load = more air + more fuel = more exhuast = spools turbo


when my car was stock i did 35 MPH in 5th gear all the time... then i did it in 4th for the next tank..... i got better milage in 4th because the more is in a better VE and breathing better...

so since i have seen both side's of the house any questions ???

[FunkZ]

I tested with my car and 1) the injectors do not cut off immediately when I let off the throttle, it takes about 5 seconds of no throttle and then they stop squirting fuel, and 2) they start pumping fuel back in once revs drop to 2000 rpm.

The exhaust note doesn't really change at all, but the popping/cracking that occurs (that sounds similar to backfiring) doesn't occur when there is no fuel in the system. I wasn't aware this was even going on, you learn something new every day.

[shenanigans]

Originally posted by Publican:
Firstly, if you have to coast in neutral to save gas in a V6, maybe you should buy a bicycle.

Secondly, coasting in neutral is idiocy - you have no control whatsoever in case of an emergency except brakes - which going down a long hill may easily fail if you have been riding them due to being in neutral in the first place.

Gear down and spend the 7 cents you might save by freewheeling.

So I take it you have never been to florida? We are not exactly known for our mountain ranges. I believe the largest hills/mountains in FL, are actually dumps.


I understand bogging the car under load isn't good, but car not bogging + low revs is good gas...


FWIW I am just above the half point on my tank and I am at 250 miles on my tank, 120 highway at 85 mph, rest all city

guessign how my gauge normally goes I think I can make it to 380-400ish miles on a tank. I will see how much gas this is on next time I need to fuel up and see how much gas I put in.

Not bad for a mostly city driven car.

Believe me I iknwo I am not saving bundles of cash... I just enjoy tinkering with cars and since I cannot race it, just screwing around.