So yesterday while leaving a parking lot

"Logansteno: Bought a VW?" (logansteno)
08/09/2014 at 13:54 • Filed to: None

I tried to depress a clutch pedal and shift gears. This didn't make sense because A) The car I was driver was a column shifted auto and B) I've NEVER driven a manual in my life.

I think it's my brain telling me to learn stick.

My girlfriend was just like, wtf are you doing?

DISCUSSION (72)

Twingo Tamer - About to descend into project car hell. > Logansteno: Bought a VW?
08/09/2014 at 13:58

Maybe in a past life you drove manual and its the memories from past you returning.

Tom McParland > Logansteno: Bought a VW?
08/09/2014 at 13:59

you have just entered....the Oppo zone!

Before I had a manual trans car I used to put an empty soda bottle in between the front bench seats, kick the floor and "shift", all my friends thought I was weird...but when it came time to do it for real I picked it right up.

Jayhawk Jake > Logansteno: Bought a VW?
08/09/2014 at 14:26

I love when I get in automatics. I always immediately slam the brake to the floor when I start the car

sm70- why not Duesenberg? > Logansteno: Bought a VW?
08/09/2014 at 14:42

Ever since I learned to drive stick, I drive with one hand on the shifter. Yeah, I occasionally use the manumatic shiftable doohickey, but that isn't really why.

Almost A Wooden Bird > Logansteno: Bought a VW?
08/09/2014 at 14:43

Not on topic, but Does anyone know how to get author permission for Oppo?

NotUnlessRoundIsFunny > Logansteno: Bought a VW?
08/09/2014 at 14:57

Sounds like Oppo is working its magic on you. :-)

Logansteno: Bought a VW? > sm70- why not Duesenberg?
08/09/2014 at 15:03

I've always driven with a hand resting on the shifter. Probably because I put the car I'm driving into neutral a lot to coast down hills.

Logansteno: Bought a VW? > NotUnlessRoundIsFunny
08/09/2014 at 15:05

Must be, now if only I could actually get my hands on a real stick shift.

Logansteno: Bought a VW? > Almost A Wooden Bird
08/09/2014 at 15:13

I shared your comment, a mod should be around at some point.

Spasoje > Logansteno: Bought a VW?
08/09/2014 at 15:16

Giant irony: I learned to drive on a manual, only driving my first automatic (a column-shifted Taurus with the front bench) a few years into my driving career. Noticed something was off when my left leg pushed into an empty footwell and my hand met air instead of a shifter. Good times.

Almost A Wooden Bird > Logansteno: Bought a VW?
08/09/2014 at 15:19

Hey, thanks!!

Logansteno: Bought a VW? > Spasoje
08/09/2014 at 15:20

I was driving a column shifted Taurus with a bench...

quarterlifecrisis > Logansteno: Bought a VW?
08/09/2014 at 15:57

When we're shuttling the old trucks around, it's a given that at some point one of us will go for the imaginary clutch in an automatic.

Now, about having done that never having driven a manual....whatever, can't help you there.

$kaycog > Almost A Wooden Bird
08/09/2014 at 16:13

I just added you to author on Oppo. Welcome!

$kaycog > Logansteno: Bought a VW?
08/09/2014 at 16:13

I got him! :D

CPT Speedbump > Logansteno: Bought a VW?
08/09/2014 at 16:32

It's your body telling you it's time to get your man card.

ThePro > Logansteno: Bought a VW?
08/09/2014 at 16:41

My dad has always driven manuals, one day we rented an auto, he drove it on the freeway, and right in front of an 18 wheeler, when he saw traffic stop, he wanted to downshift to slow down a bit. He pressed on the clutch, except there was no clutch, so he pressed on the closest pedal to where the clutch would be.

That semi was not happy..

Almost A Wooden Bird > $kaycog
08/09/2014 at 17:12

Thank you!!

driftmeister > Logansteno: Bought a VW?
08/09/2014 at 17:30

The gods have spoken. You must now get a car with a manuel transmission.

Preferably a BRZ like your chosen picture.

Logansteno: Bought a VW? > driftmeister
08/09/2014 at 17:31

I'd kill for an black FR-S.

potentialthreat > $kaycog
08/09/2014 at 18:03

can you add me too? thanks

$kaycog > potentialthreat
08/09/2014 at 18:05

Of course! I just now approved you. Welcome!

potentialthreat > $kaycog
08/09/2014 at 18:07

Thank you ;)

perkunas > Jayhawk Jake
08/09/2014 at 21:49

Do you know that you actually need to do this in order to start the car? :D

perkunas > sm70- why not Duesenberg?
08/09/2014 at 21:50

It's a bad practice. Two hands on the wheel are better, also, resting on the shifter puts wear on the tranny.

perkunas > Logansteno: Bought a VW?
08/09/2014 at 21:51

Do you know that modern engines consume zero fuel when going down a hill and in gear? It's a bad practice to coast in neutral. Also, if the engine stalls, you lose power-everything (steering, brakes etc.)

perkunas > $kaycog
08/09/2014 at 21:52

I wish I could have that.

sm70- why not Duesenberg? > perkunas
08/09/2014 at 21:55

How does it put wear on the tranny?

$kaycog > perkunas
08/09/2014 at 22:02

Ask, and you shall receive. Shazam! You are now an author on Oppo! Welcome, sir!

Jayhawk Jake > perkunas
08/09/2014 at 22:05

Of course. But I normally do right foot on brake to start. When I get in an auto now I slam it down with my left foot as if it's the clutch

Logansteno: Bought a VW? > perkunas
08/09/2014 at 22:05

If the RPM gauge shows the engine is spinning, it's using fuel. Until you have sources to show otherwise, I'm gonna keep popping my car into neutral.

perkunas > Logansteno: Bought a VW?
08/09/2014 at 22:41

Umm, no. Modern fuel injection management can cut off fuel delivery by electronically shutting down the injectors. Just check your MPG dial. If it's idling, it generally shows "—". If you're coasting in gear, it shows "0.0". Here's a sauce: http://www.popularmechanics.com/cars/alternati…

perkunas > $kaycog
08/09/2014 at 22:42

Wow, you're generous today. Big thanks. Now, how do I post...

Logansteno: Bought a VW? > perkunas
08/09/2014 at 22:47

Something tells me my 20 year old pushrod V6 doesn't do that.

perkunas > Logansteno: Bought a VW?
08/09/2014 at 22:54

If it has electronic fuel injection, it just might. Most better european cars had it 20 years ago

LocalSP > Logansteno: Bought a VW?
08/09/2014 at 23:25

My dad had always driven cars with sticks. Then he bought a new car with an automatic. I can't tell you how many times we took off from a light or stop sign only to be thrown forward by my dad hitting the brake thinking he was pushing in the clutch.

$kaycog > perkunas
08/10/2014 at 09:05

At the top left of the page are two circles. Click the blue one with the three blue lines in it. Then click "Compose post" option. A comment box will appear and then you type in your comment. At the bottom of the comment box is an orange box that says "Save as private".........click the down arrow on that box. Then click the "Save as public" option. That should put your comment at the top of the page of Oppositelock (it sometimes takes a few minutes).

I don't know why they made it so difficult, but you'll get used to it. Good luck!

BansheeNornForgotHisBurnerKey > Logansteno: Bought a VW?
08/10/2014 at 09:51

hahaha. same thing happened to me back when after years of driving an automatic (we switched to auto after mom got a hysterectomy and her doc basically told her to stop driving stick). i got to borrow my aunt's car for the weekend (manual) and after bringing it back to her, got home and was trying to start one of our cars later. i kept kicking an imaginary clutch to start it, and it turns out i was kicking the footrest. hahaha.

BansheeNornForgotHisBurnerKey > Logansteno: Bought a VW?
08/10/2014 at 09:51

thebigbossyboss > perkunas
08/10/2014 at 10:05

...you will still lose power everything if the car stalls in gear.

Vicente Esteve > Tom McParland
08/10/2014 at 11:19

Holy Crap i did EXACTLY the same! It was even weirder in my mothers Expedition, but the cup holders hold the bottle so badly, I could use it as a 6 speed.

69montego > perkunas
08/10/2014 at 11:26

Sorry, but I gotta call BS here. unless your computer is COMPLETELY shutting down the engine, it's consuming fuel. and the thing is, it'll most likely use more fuel starting and stopping the engine than idle at a steady state. For sure the emissions will be worse.

And, you can't go off of a scan tool or the trip computer in the car, they are not 100% accurate. I disagree with the premise in the article you linked to...the only way to know for sure how much difference there is is to measure the volume of fuel in to the fuel rail and out through the return line (for those cars without returnless fuel injection).

It would be interesting to see real world data on this, but I'd be willing to bet the difference would be negligible in real world applications

HFV has no HFV. But somehow has 2 motorcycles > Tom McParland
08/10/2014 at 11:53

You are not the only one that had a soda bottle shifter.

HFV has no HFV. But somehow has 2 motorcycles > Almost A Wooden Bird
08/10/2014 at 11:55

Prove your not a dick and then Ask for it.

perkunas > 69montego
08/10/2014 at 12:12

There is no need for fuel to be injected into the cylinders if you're going downhill. The gravity does its work. The same goes if you're engine braking. The ECU calculates the amount of fuel needed according to the engine load, which itself is a derivative of acceleration position, speed, rpm, etc. The engine DOES NOT completely shut down, it is still rotating, because it is in gear and the wheels are rolling. There just is no need to inject fuel, because there is zero load on the engine. Why would it dump fuel in it if the engine is not trying to pull anything? In my car, it only starts injecting fuel at around 900RPM, because that's the idle engine speed. You coast down in gear with no accelerator until it drop to 900, then it just levels out, so that the engine doesn't stall. You should read more about modern fuel injection systems. By the way, the trip computer is 99% correct on my 2001 Volvo. I checked multiple times with a full tank and the odometer. Of course, there is some error in the measurement, but it is not that big. Usually around 0.1l/100km, which is negligible from my point of view.

69montego > perkunas
08/10/2014 at 12:23

the ecm does NOT cut fuel flow to the engine unless the ignition is shut off. or in the case of cylinder deactivation at cruise speeds. and it does this by deactivating the fuel injectors. What sort of car do you drive?

If you are going off of data you are collecting from a scan tool, I can see where you might think it's killing injectors. Even during engine braking, there is still fuel being injected.

take a look at your injector pulse width(or duty cycle depending on which scanner you're usin at the time) I'll bet that you'll never see this at zero while you're driving your car (unless you turn the ignition off)

the ecm will cut it way back, but it's still firing the injectors, therefore you're still getting fuel into the cylinders

perkunas > 69montego
08/10/2014 at 13:14

Okay, you might be right on this. I drive a Volvo C70 T5.

Almost A Wooden Bird > HFV has no HFV. But somehow has 2 motorcycles
08/10/2014 at 13:36

Thanks for your kind words! I must not be too much of a dick.

69montego > perkunas
08/10/2014 at 13:37

there have been some prototypes that shut the engine totally off at a stop and start it back up, but I don't think any production car does this yet (unless it's something like a hybrid, prius or such).

you're probably going to see more stuff like this as the higher CAFE standards start to kick in.....this is also why ford is going with aluminum for the f-150 and next gen superduty.

If you ever get a chance to monitor that data in realtime, let me know.

I'm curious as to the outcome

have a good day :)

HFV has no HFV. But somehow has 2 motorcycles > Almost A Wooden Bird
08/10/2014 at 14:20

not 100 percent a dick

Kinja'd!!!

pedal-force > perkunas
08/10/2014 at 15:19

Yep. Quick way to ruin synchros. It's a no-no to rest your hand on the shifter.

Nick-Speed > perkunas
08/10/2014 at 17:49

While "Modern fuel injection management can cut off fuel delivery by electronically shutting down the injectors" as you say, they never ever cut the fuel entirely. Ever. Until you turn the car off.
I read you sauce and while it contained some verifiable theory, it tasted like bullshit and I completely understand what the author is saying.
The inertia of the drive-train and the car rolling would keep the engine spinning though the change from "zero fuel injector" time to anything up from zero would certainly be something a driver could feel, as such it would be a drivability perception no manufacturer wants, or needs, to deal with. There is very little fuel being injected as the car goes down hill but there is some. No matter what your "MPG dial" says.

perkunas > Nick-Speed
08/10/2014 at 18:34

Yeah, I get what you're saying. I might have been wrong on my part. Still, I don't see why it technically couldn't work at a zero duty cycle going downhill, that is, why "anything up from zero would certainly be something a driver could feel".

Gaspashov > Logansteno: Bought a VW?
08/10/2014 at 19:33

Try a Renault 4 ( aka "4L", not the 4Cv) ... I drove one from time to time and keep searching the stick on the floor.. (I prefer not talk about it's silly handbrake's position).

jdrgoat - Ponticrack? > Nick-Speed
08/11/2014 at 01:05

Modern cars do in fact shut off the injectors during decel. I haven't read the article, but I've known about this for years. I've always heard of it referred as "DFCO" for "deceleration fuel cut off". And yes, you can in fact feel it if you know what you're looking for. I can hear in my car when the injectors begin firing again once the revs get back to around 1500rpm, and playing with the throttle has subtle but noticeable clues that the injectors were off.

jdrgoat - Ponticrack? > 69montego
08/11/2014 at 01:08

Many, many cars (moreso in Europe) have start-stop technology and have had it for years. They're less common in the US, but even American cars are getting it even though the EPA testing methods don't show any improvements.

Also, EFI systems have for years done exactly what we've been saying, shutting down the injectors during decel.

Nick-Speed > jdrgoat - Ponticrack?
08/11/2014 at 08:03

The discussion was not deceleration, it was "when going down a hill and in gear", "knowing about something for years" is hardly the same as verifiable fact. Engines do get very close to zero fuel injector on deceleration, individual injectors will be off for a given time, all of then off at the same time never happens.

Nick-Speed > jdrgoat - Ponticrack?
08/11/2014 at 11:12

The discussion is completely unrelated to stop-start. See above.

SantaRita > Logansteno: Bought a VW?
08/11/2014 at 11:43

it's kindof like when you lose a limb, but you can still get "ghost" sensations....but in reverse.

jdrgoat - Ponticrack? > Nick-Speed
08/11/2014 at 13:09

I was replying to 69montego, who brought up start-stop himself. DFCO and stat-stop are unrelated technologies, I agree.

jdrgoat - Ponticrack? > Nick-Speed
08/11/2014 at 13:18

"when going down hill and in gear" is the same as slowing down on a level surface as far as the drivetrain is concerned. Both times you can use engine braking to slow down or maintain speed. And if you are arguing that it takes less work/fuel for an engine to idle than to coast down, I think you should take a step back and rethink that. If you're arguing that 0.02 gal/hr is not negligible, then I guess you're right. 0.02 > 0.00, but 0.02 < 0.80.

Nick-Speed > jdrgoat - Ponticrack?
08/11/2014 at 16:43

Those 2 are not the same, going down hill the throttle will be open, maybe as low as 1-2% open, but open. Slowing down on a level surface your foot is probably completely off the throttle. Both will have very little injector time on (open squirting fuel) but but they are on. I'm not arguing anything but that.

jdrgoat - Ponticrack? > Nick-Speed
08/11/2014 at 22:07

Which is more efficient: Putting the transmission in neutral and coasting down, or putting the transmission in a lower gear and engine braking? Because that's really what got this whole "no fuel vs very little fuel" thing started.

Nick-Speed > jdrgoat - Ponticrack?
08/12/2014 at 00:14

You're coming up with a new scenario with every reply, is their a point to that? None of them are the same. Under no conditions ever (with the car running) do the fuel injectors (as a set) stop injecting fuel. Ever.

Neutral coasting will use less fuel than wailing the engine up at 3 grand or so, under any load conditions.
There is never a scenario with the key on and the car running (uphill, downhill or sideways, throttle open, closed, or somewhere in between) when the fuel injectors (as a set) stop injecting fuel. Individually the injectors, in some sequence, will be closed for some periods of time. Collectively that simple doesn't happen, if it does it's called "stalling".
What you say is not what got this discussion started.

jdrgoat - Ponticrack? > Nick-Speed
08/12/2014 at 03:00

What got this conversation started was this:

Your initial argument appears to be drawing a very fine line between "no fuel" and "next to no fuel." To which I succeeded, If you want to call 0.02 gal/hr not "no fuel", then technically, yes, you are correct. But it is drastically less than the fuel that it takes to idle an engine.

Idling an engine is what you will be doing if you coast in neutral. Coasting down using engine braking ("wailing the engine up at 3 grand or so") will use the inertia of the vehicle spinning the tires to keep the engine spinning without fuel. This will not cause a stall. If you were to force the engine to stop spinning (completely stall) while you're driving and not in neutral, the driven wheels would lock up. Anyone who has ever done a money shift has felt a similar effect to this.

If we were still using a carburetor, then yes we would be wasting fuel, as the incoming air would cause more fuel to flow in, regardless of throttle position.

You're accusing me of changing my position, I'm not sure why. I'm just not sure why you can't take a step back and realize that the tires are spinning the engine, NOT FUEL, when you're engine braking (aka DFCO). That's negative acceleration, which is a load condition where there is less than zero need for fuel.

If you think that there is fuel being injected, tell me what logical reason there would be a need for it.

Nick-Speed > jdrgoat - Ponticrack?
08/12/2014 at 09:41

There is a fine line"no fuel" and "next to no fuel" though I certainly don't contend that 0.02 gal/hr is no fuel and never said so.

There is never a scenario (including your most recent scenario) with the key on and the car running (uphill, downhill or sideways, throttle open, closed, or somewhere in between) with the engine spinning under load (or not as in your latest scenario) when the fuel injectors (as a set) stop injecting fuel. Individually the injectors, in some sequence, certainly will be closed for some periods of time, using very little fuel, but still some fuel.
I fully realize that the inertia of the vehicle moving would indeed keep the drive-trian spinning.

The logical reason is this: the transition from "zero fuel injector" time to anything up from zero would certainly be something a driver could feel, as such it would be a drivability perception no manufacturer wants, or needs, to deal with.

Explore your theory in a manual trans car, when coasting down a decent hill at zero throttle input in a gear that make the engine spin at 3 grand or so, turn the key off (not to lock which would be unsafe for civilians) then on, off, on, how ever many times you need to. All else being the same you will feel difference, a transition, between the key on (very little fuel) and key off (zero fuel).

swansong, rockin' the wagons > 69montego
08/12/2014 at 12:37

As counter intuitive as it sounds, modern (around OBDII and newer) fuel injected cars will shut the injectors completely off in certain deceleration situations. Most notably when decelerating in top gear (auto or manual!) from highway speeds. What's happening is the momentum from the car is turning the wheels, and through gearing and transmissions, turning the engine. The engine basically acts as an air pump at this point, hence the engine braking. When the RPMs get low enough, the injectors turn back on and you're using fuel again. It's been faintly noticeable on the last three cars I've owned. It may not save a bunch of fuel, but it helps, and is certainly safer than neutral coasting.

And yes, a proper Scangauge or Torque app will be 100% accurate. It's pulling data directly through the OBDII and CAN interfaces, and reporting exactly what is in the cars ECU. It's possible that the ECU is being lied to by faulty sensors, but that's a separate issue.

jdrgoat - Ponticrack? > Nick-Speed
08/14/2014 at 04:21

I agreed with you that 0.02 gph is more than zero fuel. That was a concession that I made because it appeared we were getting more "technically" and "theoretically" than just casual, where rounding "nearly zero" to "zero" for an implied all practical purposes type of scenario.

Where you say my "most recent scenario", I'm confused why you're accusing me of changing the situation I'm talking about. Any instance where the engine sees no load it has no reason to burn fuel. One of the beauties of fuel injection over carburetion is that we can make this happen. This can include, and is not limited to, going down hill without applying throttle (implies not using cruise control), downshifting to a "wailing 3000 rpm" to take advantage of engine braking to assist slowing down coming to a red light (hill or not, makes no difference), or even when applying zero throttle after downshifting and into a braking zone on a race track. As far as the engine cares, these are all the same "scenario."

"Individually the injectors, in some sequence, certainly will be closed for some periods of time, using very little fuel, but still some fuel." - Nick-Speed

Yes. During normal driving conditions which include accelerating, the fuel injectors operate in a pattern which will include periods in which they are closed. The injector duty will be determined by many things, some included are engine temperature, intake air temperature, engine rpm, throttle position, etc. The sequence is not "some sequence," but in fact it will follow the firing order of the engine, assuming that we're using a modern fuel injection system (most cars newer than the 80's) and not something like TBI.
I'm not sure if this is intended, but it looks like you're saying that when the injectors are closed they use, "very little fuel, but still some fuel." Perhaps I'm reading into that far too literally, because I hope that that's not what you're trying to say.

I see how that logically makes sense. And it does make sense. You've just come close to the correct conclusion, but it's not the correct conclusion.

Yes. There is a drivability perception. And the way to overcome that is not to waste fuel when it's not needed, which would also erase some of the longevity gains that fuel injection has allowed over carburetion. The way to overcome the driver's perception of the transition between the injectors not firing to them firing again is in the fine tuning. It's not like there's much to feel, as either way the engine is making 0 net HP. I'm not sure if you're assuming there would be a jolt, but there's not.

It's funny, because I was going to suggest also to you that you try seeing if there's a difference during engine braking if you have the key on or the key off with a manual transmission vehicle. I mentioned earlier that "…yes, you can in fact feel it if you know what you're looking for." [Monday 1:05am (CST)] So as to not be unreasonable, I did try it out and turned the key off while engine braking for red lights. And you know what, there was no difference. The car behaved the same. The car sounded the same. I was kind of weirded out seeing my gauges go to zero, but that's just because the car was shut off. The only thing that indicated the injectors were off (both with the key on and the key off) was the lack of burble and popping from the exhaust. You can hear that come back when the engine revs dropped below 1500rpm, and that's the only perceptible difference.

You make it sound like no one wants to feel *anything*, and if that were the case we would all be driving essentially Mercedes S-classes, or Lexus ESs, only with CVTs and popping xanex at every intersection. Speaking of CVTs, even a base model Nissan (CVT equipped) holds the engine at about 4000rpm in my experience when you shift it into L. I know you don't trust in dash mpg readouts, but even a base Nissan with a CVT in L will peg to their top value if you release the throttle 100%. (I'm skeptical of the gauges myself, but have found my car to be relatively close over many, many tanks. And it's actually 99% of the time pessimistic.)

Now. I just want to get a little mathy here. In my car, the injectors will be off during engine braking until it's below 1500rpm. For an example, let's say that I'm engine braking by downshifting into 5 th which puts the engine at a still leisurely 2000rpm. In my car, this would be roughly 52.7mph. The highest that the "instant mpg" gauge in my car goes is 99.9 mpg. Well now, we have enough information to find instantaneous fuel flow.

99.9mpg / 52.7mph = X gph. Solve for X.

If you want to tell me that at the minimum, the situation which would bode best for your point of view, I'm using nearly 2 gal/hr only to slow down ? That's the average fuel rate that I use while in my daily commutes with a 40mph average speed (calculated average speed, no guesses here).

My car burns about 0.85 gph to idle. If I were to put my transmission into neutral during this same scenario, I would only see roughly 44.795mpg, and there is no way that my pessimistic gauge is that far off.

Nick-Speed > jdrgoat - Ponticrack?
08/14/2014 at 09:35

Well there's a lot of theory in your explanation, and that's fine. There is some in mine also. You're saying that all the scenarios are actually the same. I do not agree with that. The ECU know a lot more than just throttle position and engine RPM.

I've explained my drivability rationale as to why it's not sound to shut off all the injectors at once but here's another. From experience in a traditional torque convertor automatic, at speeds under 30 mph, closed throttle and coasting, I turn the key to off (from run), there is not enough "push back" of fluid from the transmission side of the torque convertor turbine (which at that point is being driven by drive train inertia) to keep the engine spinning. The engine stops running and I have to shift to neutral and restart the engine. At say 50 mph-60 mph this doesn't happen. I've tried that also.

When the injectors are closed they use NO FUEL. Any time (even nanoseconds) they are open the engine is using that fuel.

In a nutshell you are saying that any time the throttle is closed and the car is rolling the ECU just shuts down all the injectors and relies on the inertia of the drive train to keep the engine spinning and at some point senses (based on inputs) a need to squirt some fuel to keep the engine running. Your justification for this seems to be that it performs these actions simply because it can. I know it can also.

In a nutshell I'm saying that the ECU never shuts down all the injectors at the same time under any no throttle input coasting situation scenarios. The injectors do squirt a minuscule amount of fuel under these scenarios.

I'm prepared to be wrong though I don't believe I am. I don't think any factory MPG gauge has the ability to prove conclusively either point of view though they certainly can be informative and fun.

jdrgoat - Ponticrack? > Nick-Speed
08/16/2014 at 21:27

Theory? Show me what looks like theory to you.

You're saying that all the scenarios are actually the same. I do not agree with that. The ECU know a lot more than just throttle position and engine RPM. - Nick-Speed

!!! UNKNOWN CONTENT TYPE !!!

The injector duty will be determined by many things, some included are engine temperature, intake air temperature, engine rpm, throttle position, etc. - jdrgoat

And that's just a tiny part of the list. There are thousands of parameters that the ECU monitors. All the scenarios I listed,

Any instance where the engine sees no load it has no reason to burn fuel. […]This can include, and is not limited to, going down hill without applying throttle (implies not using cruise control), downshifting to a "wailing 3000 rpm" to take advantage of engine braking to assist slowing down coming to a red light (hill or not, makes no difference), or even when applying zero throttle after downshifting and into a braking zone on a race track. As far as the engine cares, these are all the same "scenario. - jdrgoat

These are all scenarios where there is zero load. All the engine sees is load, and that's all it cares about. It bases its response on the multitude of sensors and parameters in the ECU, but in the end all it cares about is load .

You never mentioned if you downshifted or what the engine speed was when you do it. That's a huge part of what we're talking about here. I don't know exactly what automatic you're driving, but there's a lot of variety even in torque converter automatics. I don't drive automatics myself enough to know if a more modern one would keep the torque converter locked up if the key was shut off. I'm inclined to believe it would not. But you still have the fluid running the converter at least a little, which would keep the engine spinning. And that right there will save you fuel. Not shut the injectors off entirely, as you noticed the fluid doesn't transfer enough power to spin it on its own.

Any situation where it is possible and prudent. This requires the rpm to be high enough. I'm not only saying that 'it can', but that it has literally no reason not to. In addition to that, it has many reasons why it's beneficial to not use fuel. Every reason not to quirt fuel, no reason why it should, and the ability to do that. Win-win and no one will ever notice (apart from marginally better fuel economy) as long as the tuning is good.

I'm prepared to be wrong though I don't believe I am. I don't think any factory MPG gauge has the ability to prove conclusively either point of view though they certainly can be informative and fun. - Nick-Speed

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…and with an oscilloscope, measuring the leads leading into the fuel injectors. The signal controlling the injector is a 12-volt square wave. - PM

I finally got around to reading the link in here. And it was way more informative than I assumed based on your reaction. The oscilloscope shows even better what the car does when you're engine braking. (Note, there is a difference between "coasting" and "engine braking".) My example was only with a couple gauges in my car and not an oscilloscope because that's all I had available, but the difference between engine braking (wailing rpm, etc) and coasting (in neutral and unsafe) is still stark.

One last go at this, and then I'm done.

If I were to jack my car up and put it on jack stands, turn the ignition on, and then hook up a pneumatic impact gun to the crank bolt and rotate the engine up to 1000 or more rpm... Would my fuel injectors fire? What if it were 2000rpm? The engine is spinning, and the car is on. That meets your criteria.

Nick-Speed > jdrgoat - Ponticrack?
08/18/2014 at 12:29

You're just throwing a bunch of bullshit in now.
Life is short, this is long.
I am right you, are wrong.

jdrgoat - Ponticrack? > Nick-Speed
08/18/2014 at 19:08

Ha. Enjoy yourself. I'm done internet arguing. :)