Insanely Good Gas Mileage Out Of N/A Modded tC
09-26-2006, 08:57 PM
#61
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Originally Posted by flintgauge86
To say that you want to save your breaks and use engine breaking is like saying you want to power shift so you don't wear out your clutch...
Not nearly the same but i see where you were going.
Not doubting you but please clear it up for me, should i go to neutral and use the brakes or stay in gear and use the brakes.
09-26-2006, 09:06 PM
#62
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Originally Posted by flintgauge86
The most fuel effecient speed is the lowest possible speed (without lugging) that you can travel at, in your highest gear. For the tC that's going to be about 45. This formula translates to the fastest speed while maintaining the lowest RPMS. I travel at 45 in my 350Z in 6th gear at about 1,600 RPM and the computer says I'm getting like 43MPG, the only thing is stopping at traffics lights, and acceleration drop the average back down to about 27. IT's absoulely insane to think that engine braking is more effecient than neutral coasting. The tC idles a 800 RPM after finishing it's warm up dance( correct me if i'm wrong on the idle, it's been a while since I drove a tC). So if you're traveling down a hill at 45 MPH, the tC will be running at about 2K RPM, which is 1200RPM more than Idle , which means the engine is demanding that much more fuel to keep going. IF youre theory of the fuel cut off and the wheel powering the engine is correct, go drive down a hill, leave the car in gear, and turn off the car. You're driving wheels will lock up so fast and send you all over the road... why, becuz the engine stops spinning, so the wheels stop spinning. If you don't believe me, go try it, and then tell me how you screwed up your car in the process, cuz it will. Engine braking is hard on the engine and causes excess wear and tear on it. The use of engine braking was introduced when cars still had drumb breaks which quickly overheated and fade out, so the drivers would downshift to slow down the car, to aviod overheating the breaks and crashing into the bushes when the faded. Todays modern cars have advanced disc brakes with vented rotors, Brake force distribution, ABS, and high heat capacity calipers, with pads that are designed to wear out and be replaced. Please, PEOPLE,just use your brakes. It's better for you milage and your engine. To say that you want to save your breaks and use engine breaking is like saying you want to power shift so you don't wear out your clutch...
09-26-2006, 09:07 PM
#63
there is nothing wrong with engine braking unless its from very high rpms.
"Advanced brakes' dont mean anything. its friction. wow. and those other features are safety features, not heat-related.
ive switched my key to just ACC many times to prove the injectors dont run without the throttle being pressed, and the motor is still spinning. period. try it before you talk all this nonsense about it.
a friend of mine and i had the argument abou this in gear out of gear thing on mileage. so far everyone in my circle of friends has tried it and saved gas by just coasting in gear as opposed to hitting neutral. not only are they saving brakes, but gas. i personally only got 27mpg when i first learned to drive stick, and i was slow. now i get 27 normally, because i coast as much as i can, and downshift as i approach stop signs or red lights, and save brakes. my engine does not get anywhere near redline in the process to add that excessive wear and tear.
so please, for the sake of knowing what you're talking about, try it. it wont hurt.
"Advanced brakes' dont mean anything. its friction. wow. and those other features are safety features, not heat-related.
ive switched my key to just ACC many times to prove the injectors dont run without the throttle being pressed, and the motor is still spinning. period. try it before you talk all this nonsense about it.
a friend of mine and i had the argument abou this in gear out of gear thing on mileage. so far everyone in my circle of friends has tried it and saved gas by just coasting in gear as opposed to hitting neutral. not only are they saving brakes, but gas. i personally only got 27mpg when i first learned to drive stick, and i was slow. now i get 27 normally, because i coast as much as i can, and downshift as i approach stop signs or red lights, and save brakes. my engine does not get anywhere near redline in the process to add that excessive wear and tear.
so please, for the sake of knowing what you're talking about, try it. it wont hurt.
09-26-2006, 09:13 PM
#64
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Originally Posted by dziuniek
still... I've noticed that lots of cars have higher mileage w/ auto nowadays, which I think is complete poop. I guess no one assumes that if you have a 1.5mile hill you can put it in neutral, but thats just me haha....
09-26-2006, 11:30 PM
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I'm not saying engine braking is going to screw up your car, it's just going to put excess and un-needed load on the engine. Why put that added wear and tear on your engine when you can replace your brake pads for like 50-100 dollars vs. engine work which can be in the thousands?I'm not talking about just letting off the gas to slow up a bit, I'm talking about the people you downshift consecutively and barely use their breaks. Someone pointed out that Mercedes did a study where they would accelerate moderately fast to a certain speed, say 60mph, and then coast for about 5 times the amount of time the accelerated, having lost speed during coasting they would return to that same speed, and repeat the process over and over. Sounds annoying and boring, but they claimed it double their MPG.
I know I mentioned some brake systems that have nothing to do with heat capacity, I was mearly trying to drive the point that our breaks have become so adanced compared to the early days of 4wheel drum brakes. If you want to really save gas, accelerate moderatley, use your highest gear possible on the straights, and coast down the hills, in nuetral, out of gear, clutch out as welll. Don't coast in gear with the clutch in, or idle at the stop lights with it in, that's not good for the clutch either.
I know I mentioned some brake systems that have nothing to do with heat capacity, I was mearly trying to drive the point that our breaks have become so adanced compared to the early days of 4wheel drum brakes. If you want to really save gas, accelerate moderatley, use your highest gear possible on the straights, and coast down the hills, in nuetral, out of gear, clutch out as welll. Don't coast in gear with the clutch in, or idle at the stop lights with it in, that's not good for the clutch either.
09-27-2006, 12:01 AM
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Originally Posted by flintgauge86
And if the wheels can power the engine, why doesn't my car roll away every time I leave it in gear with the e-brake off??? 
I apologize if you were just joking
Originally Posted by hunterUnknown
so then, idiotwork aside, if you coast in gear without high rpms and moronic behavior, you can save gas. agree?
That's why its not always as simple as getting into the highest gear possible without lugging.
09-27-2006, 12:03 AM
#68
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Originally Posted by flintgauge86
IF youre theory of the fuel cut off and the wheel powering the engine is correct, go drive down a hill, leave the car in gear, and turn off the car. You're driving wheels will lock up so fast and send you all over the road... why, becuz the engine stops spinning, so the wheels stop spinning. If you don't believe me, go try it, and then tell me how you screwed up your car in the process, cuz it will.
It does not lock the wheel up whatsoever. Have you ever tried tighting a lug nut with the car in gear..the wheel spins right.
09-27-2006, 12:08 AM
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Also if you somehow managed to lock up your front wheels during driving (unlikely given the fact our cars have ABS), your engine would stall.
If you were to immediately get off the brakes, the engine would bump start again (assuming you still have momentum).
With that said, you cannot bump start the car without having the key in the start position. The computer won't allow spark to happen within the engine unless that condition is set.
Anyhow, this thread has gone severly offtopic with an argument where its obvious we're not going to change anyone's opinions... so let's try to get it back on topic.
If you were to immediately get off the brakes, the engine would bump start again (assuming you still have momentum).
With that said, you cannot bump start the car without having the key in the start position. The computer won't allow spark to happen within the engine unless that condition is set.
Anyhow, this thread has gone severly offtopic with an argument where its obvious we're not going to change anyone's opinions... so let's try to get it back on topic.
09-27-2006, 12:13 AM
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Originally Posted by Dr_Isotope
Quoting from the Wiki is tantamount to quoting quantum physics via Paris Hilton.
09-27-2006, 12:27 AM
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^^ heh, in one of my literature special topic classes my professor, on the first day of class, when to a random article on wikipedia (I think about freud), and changed one of the dates there, and left it like that; he wasn't registered or anything either.
It was to prove a point, but it was pretty obvious he hated wikipedia
It was to prove a point, but it was pretty obvious he hated wikipedia
09-27-2006, 01:22 AM
#73
Originally Posted by hunterUnknown
so then, idiotwork aside, if you coast in gear without high rpms and moronic behavior, you can save gas. agree?
Here's a theoretic situation.
Take two identical tCs, and tow them behind two identical RVs, at 60mph.
tC #1 will have it's engine on, and be in 5th gear.
tC #2 will have it's engine on, and be in neutral.
Which car do you think will use more fuel? Neither car has to overcome it's own weight, as it's being towed behind a giant metal monster.
More RPMs = more fuel use. It's simple... or at least I thought it would be.
09-27-2006, 01:35 AM
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how bout this...
Idle being towed = 800 rpms using fuel to idle
5th gear being towed = 2000 rpm's with injectors shut off = no fuel
if you really want to get into it, as you keep saying that its using fuel in 5th gear and 0% throttle then which car is "eaiser" to tow? the car with the enging being turned by the wheels is going to be much harder to tow than they one that has the gearbox disenguaged. The car in 5th grea would me MUCH harder to tow because there is no fuel keeping the engine at a constant rpm.
Idle being towed = 800 rpms using fuel to idle
5th gear being towed = 2000 rpm's with injectors shut off = no fuel
if you really want to get into it, as you keep saying that its using fuel in 5th gear and 0% throttle then which car is "eaiser" to tow? the car with the enging being turned by the wheels is going to be much harder to tow than they one that has the gearbox disenguaged. The car in 5th grea would me MUCH harder to tow because there is no fuel keeping the engine at a constant rpm.
09-27-2006, 01:48 AM
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the more i read this thread it basicly comes down to:
A) DFCO exists - then engine breaking saves gas
or
B) DFCO does not exist - Idle/neutral saves gas
and the only one who can tell us which one concerns our cars is someone who can moniter thier ECU and tell us if DFCO is enabled or not. All this hypthetical garbage doesnt mean crap without the knoweldge of the DFCO
A) DFCO exists - then engine breaking saves gas
or
B) DFCO does not exist - Idle/neutral saves gas
and the only one who can tell us which one concerns our cars is someone who can moniter thier ECU and tell us if DFCO is enabled or not. All this hypthetical garbage doesnt mean crap without the knoweldge of the DFCO
09-27-2006, 01:50 AM
#76
I don't know who told you folks that the fuel supply is cut off without throttle input. Because it isn't That's not how internal combustion engines work-- aside from variable displacement engines, which are built to do so.
09-27-2006, 01:59 AM
#78
And what has led you all to beleive that every fuel injected car on the road is fitted with the mythical "DFCO"? You're basing your entire argument on speculation, rather than actually driving the car.
09-27-2006, 02:17 AM
#79
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http://www.autoshop101.com/forms/h43...el%20cutoff%22
look at page 7
http://www.autoshop101.com/
Technical Articles
Toyota Series - Engine Performance OBD-II
43 Fuel System#2 - Injection Duration w/ques.pdf file size 173KB
looks to me like its not some mythical creature, do a little more research...
look at page 7
http://www.autoshop101.com/
Technical Articles
Toyota Series - Engine Performance OBD-II
43 Fuel System#2 - Injection Duration w/ques.pdf file size 173KB
looks to me like its not some mythical creature, do a little more research...
09-27-2006, 02:35 AM
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Originally Posted by Jayjr
the more i read this thread it basicly comes down to:
A) DFCO exists - then engine breaking saves gas
or
B) DFCO does not exist - Idle/neutral saves gas
A) DFCO exists - then engine breaking saves gas
or
B) DFCO does not exist - Idle/neutral saves gas
i was always under the impression of everything that isotope has said. higher rpms, more gas.
so i guess our only solution here is to test this idea of DFCO. i too, shall drive the next few tanks or so using engine braking and leaving in gear, as i current disengage when going downhill or approach a stoplight....i shall update you guys when i have something. i suggest everyone that is arguing to do the same (well, the opposite of what you're currently doing) and we will all reconvene and see what we get.
agreed?