Insanely Good Gas Mileage Out Of N/A Modded tC
09-27-2006, 06:02 AM
#101
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It just gets better.
Testing my car now for mileage on premium. I am aware of the burn rates of fuel based on octane levels but I just wanted to see if the car would bump up timing and notice the octane boost and possibly get better mpg.
My old car was not near techically advanced enough to notice possible knock and learn fuel trims.
Testing my car now for mileage on premium. I am aware of the burn rates of fuel based on octane levels but I just wanted to see if the car would bump up timing and notice the octane boost and possibly get better mpg.
My old car was not near techically advanced enough to notice possible knock and learn fuel trims.
09-27-2006, 08:25 PM
#102
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Ok, I am all for finding the truth here, so on my way home from work today I reset the MPG computer on my Z. It updates every 30 seconds. SO I did 4 trial runs, 2 coasting down hill in neutral and 2 engine braking in 6th gear. I did u-turns and did the same two hills for both experiements ( for the sake of science). When coasting in neutral I got 52 and 99.9 (it really said it too) MPG, on the other hand, going down hill in 6th gear with my foot off the gas yielded only 22 and 43 mpg. It's just a simple little experiement and I tried to remove as many variables as possible. So there it is boys, take it as it is.
09-27-2006, 08:33 PM
#103
i hardly see how a mpg computer is right in any way in a few hill runs. you have to incorporate driving ideals into your daily driving. not a short-term one-day thing.
my mom's bmw 330's mpg gauge drops sub-12 upon tapping the gas pedal.
my friend's prius shows well over 70 most of the time but they dont get that. sometimes it'll show 40 but they'll get 50.
i'm still curious to see what isotope brings back in findings.
my mom's bmw 330's mpg gauge drops sub-12 upon tapping the gas pedal.
my friend's prius shows well over 70 most of the time but they dont get that. sometimes it'll show 40 but they'll get 50.
i'm still curious to see what isotope brings back in findings.
09-27-2006, 10:28 PM
#104
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I understand what you are saying, about your MPG averaging out over time, but I wasn't arguing that. I was trying to prove that engine braking is less fuel effecient than coasting in nuetral. And you're right, a more long term thorough testing would be more accurate and conclusive, but I had to work today and do homework. I don't have the time or money for gas to drive around for hours. I said it was My small contribution to science. Anyone wanna donate some gas money for science?
09-27-2006, 10:47 PM
#105
just change the way you drive. and dont watch your "mpg computer" because its kind of like going outside and saying "it kinda feels like 80..."
it's about on par in accuracy.
it's about on par in accuracy.
09-27-2006, 10:52 PM
#106
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My computer displays real time milage and average milage and there's no disputing the fact that while coasting in neutral I got 2-3 times better real time MPG than I did while engine braking over the same hill.
09-27-2006, 11:19 PM
#107
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I concede the possibility that auto manufacturers have decided in the past few years to still squirt a little gas in the engines when decelerating, to keep the cylinders warm, but that would be a conscious choice programmed into the ECU software. It is a fact that many/most engines since the mid 80's have been programmed to shut off the flow of gas 100% when the throttle is released completely until the rpms drop to near idle.
09-27-2006, 11:41 PM
#108
unfortuantely, like most topics on this forum, people take their preconceptions and cocky attitudes about how something works and believe it to be fact without thinking about the physics of it all. posts about "facts" are much more respectable when backed up with something, and most simply just state their opinion without backup.
while our cars will maintain an idle when possible, there is no reason fuel injection will occur without the throttle opening to let in air first. the throttle is controlled by your gas pedal, or the idle control. if your clutch is engaged and you're in gear, and not on the gas, your engine becomes a compressor, and works as resistance against your wheels to slow you down. yes, forceful compression. what an amazing concept.
seaching google for "how engine braking works" bring up numerous results supporting the simple, yet oddly refuted fact i stated. here is one such resulted page:
http://everything2.com/index.pl?node...&lastnode_id=0
they state shifting to neutral as this will NOT cause decelreration due to engine braking. efficiency is key here, not necessarily zero fuel consumption.
but the fact remains, whether you're rolling down a 40 mile hill, or just coasting: if you're in gear and off the throttle, you use NO fuel. any simple understanding of a car's drivetrain will achieve agreement.
period.
i dont know what is hard to understand about that.
edit: heres more proof.
http://www.ecodrive.org/index.php?id=228
while our cars will maintain an idle when possible, there is no reason fuel injection will occur without the throttle opening to let in air first. the throttle is controlled by your gas pedal, or the idle control. if your clutch is engaged and you're in gear, and not on the gas, your engine becomes a compressor, and works as resistance against your wheels to slow you down. yes, forceful compression. what an amazing concept.
seaching google for "how engine braking works" bring up numerous results supporting the simple, yet oddly refuted fact i stated. here is one such resulted page:
http://everything2.com/index.pl?node...&lastnode_id=0
* "Another thing to save fuel is to always use engine braking. Doing so, the car's momentum drives the engine and NO fuel is consumed. Better than idling, thus. Can be used on automatics as well as stick shifts."
(idea) by WolfKeeper (19.7 hr) (print) ? 1 C! Sat Jan 18 2003 at 3:26:31
The above voluminous information, is all true, but most of the effects are pretty small (for example tyre pressure has to be down by a massive 30% to give a 10% increase in fuel consumption), and misses the single biggest, most effective technique of all.
Actually the best way to decrease fuel consumption is sometimes called 'squirt and coast'.
To do this you accelerate using moderate to firm acceleration (choose gears to give about 1/3-1/2 max engine revs or whatever is most efficient for your engine for accelerating) up to a target speed (a speed like 56 mph is OK, but the lower the better due to air drag; 30 mph is better ;-) ). You should try to get about 20-25 miles per hour whilst accelerating depending on the engine.
When you reach your target speed you drop the clutch (or put the car into neutral), and coast with the engine idling. You should easily get more than 50 mpg whilst you are coasting, even on a real gas guzzler, probably well over a hundred mpg on an average car.
You should aim to coast for a few times longer than you accelerate for. When you've lost say, 10-15 mph, accelerate back up to your target speed. Lather, rinse, repeat.
(idea) by WolfKeeper (19.7 hr) (print) ? 1 C! Sat Jan 18 2003 at 3:26:31
The above voluminous information, is all true, but most of the effects are pretty small (for example tyre pressure has to be down by a massive 30% to give a 10% increase in fuel consumption), and misses the single biggest, most effective technique of all.
Actually the best way to decrease fuel consumption is sometimes called 'squirt and coast'.
To do this you accelerate using moderate to firm acceleration (choose gears to give about 1/3-1/2 max engine revs or whatever is most efficient for your engine for accelerating) up to a target speed (a speed like 56 mph is OK, but the lower the better due to air drag; 30 mph is better ;-) ). You should try to get about 20-25 miles per hour whilst accelerating depending on the engine.
When you reach your target speed you drop the clutch (or put the car into neutral), and coast with the engine idling. You should easily get more than 50 mpg whilst you are coasting, even on a real gas guzzler, probably well over a hundred mpg on an average car.
You should aim to coast for a few times longer than you accelerate for. When you've lost say, 10-15 mph, accelerate back up to your target speed. Lather, rinse, repeat.
but the fact remains, whether you're rolling down a 40 mile hill, or just coasting: if you're in gear and off the throttle, you use NO fuel. any simple understanding of a car's drivetrain will achieve agreement.
period.
i dont know what is hard to understand about that.
edit: heres more proof.
http://www.ecodrive.org/index.php?id=228
Decelerate smoothly
When you have to slow down or to stop, decelerate smoothly by releasing the accelerator in time, leaving the car in gear!
Petrol and diesel cars manufactured from 1990 onwards, are generally equipped with fuel injection combined with an electronic function that cuts off the engine's fuel supply under engine braking (accelerator released and a gear engaged). The advantages of this fuel cut off function can be used by releasing the accelerator in time, for example when approaching traffic lights. This also reduces wear and tear on the brakes, reducing maintenance costs. Engine braking, not only has a positive effect on fuel consumption, but also on exhaust emissions, traffic safety, traffic flow and passenger comfort.
When you have to slow down or to stop, decelerate smoothly by releasing the accelerator in time, leaving the car in gear!
Petrol and diesel cars manufactured from 1990 onwards, are generally equipped with fuel injection combined with an electronic function that cuts off the engine's fuel supply under engine braking (accelerator released and a gear engaged). The advantages of this fuel cut off function can be used by releasing the accelerator in time, for example when approaching traffic lights. This also reduces wear and tear on the brakes, reducing maintenance costs. Engine braking, not only has a positive effect on fuel consumption, but also on exhaust emissions, traffic safety, traffic flow and passenger comfort.
09-28-2006, 12:50 AM
#109
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My little experiement is probably skewed cuz my 350Z is probably programmed to burn gas as much as possible, and most likely keep feeding the engine fuel even during engine braking to avoid throttle lag, since it is a factory built track car, and gas milage is of little or no concern to the prospective buyers and current owners of such a car.
09-28-2006, 04:31 AM
#111
so until we hear from isotope about his findings, lets call this a day finally.
in the mean time, im trying the gas/coast method. in other words, im going to see the effects on mileage from accelerating to a higher-than-usual speed, and then hitting neutral for a duration until speed is "too low" and then accelerating again. we'll see what happens i guess.
in the mean time, im trying the gas/coast method. in other words, im going to see the effects on mileage from accelerating to a higher-than-usual speed, and then hitting neutral for a duration until speed is "too low" and then accelerating again. we'll see what happens i guess.
09-28-2006, 04:43 AM
#112
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Indeed, I wouldn't be so fast to trust the computer on your Z. On the way to Philly, I drove my sister's Altima. We drove it for about 13 hours or so at anywhere from 75-90 mph. The computer reported mileages up to 40! There's no way I'm going to believe that (a 2.5L Nissan engine + a car full of college stuff + 4 people + windy day != great mileage). Your Z is going to have the same computer, or at least the same algorithms for calculating mileage (they are both Nissans).
That's my input to this thread, and seeing how it has progressed, probably my last post. I think what needs to be said has come out in a way where it is no longer obscured by nonsense. There's no more use to this thread.
I think hunter said it best, let's just call it a day.
That's my input to this thread, and seeing how it has progressed, probably my last post. I think what needs to be said has come out in a way where it is no longer obscured by nonsense. There's no more use to this thread.
I think hunter said it best, let's just call it a day.
09-29-2006, 01:51 PM
#116
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Holy crap, how could you have not ever... Oh I see. You're 19. Gawd that makes me feel old. It's a reference to the third movie in a post-apocalyptic earth trilogy, "Mad Max Beyond Thunderdome". http://imdb.com/title/tt0089530/
Thunderdome was where the primitive society of Bartertown battled out with other towns people over civil disagreements. It was more of a deterrent than a solution, but also served the purpose of providing the primitive town with 'bread and circuses' like the Romans did for their subjects.
Whew.. That was a hell of a sociological analysis.....
Thunderdome was where the primitive society of Bartertown battled out with other towns people over civil disagreements. It was more of a deterrent than a solution, but also served the purpose of providing the primitive town with 'bread and circuses' like the Romans did for their subjects.
Whew.. That was a hell of a sociological analysis.....
10-15-2006, 07:58 PM
#117
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Hey guys I am also seeing extra fuel being injected with engine braking and if you get the rpms up to about 3000 and more it adds a lot of gas like .3 to .4 gph instead of the usual .2 to .1gph at idle in my xB. This is according to my ScanGauge computer so I usually pop it in neutral and wear the brakes a little - actually with the xB you have to use power to get down hills due to the air drag. I have a feeling that to keep the emissions clean it keeps some fuel flowing otherwise you end up pumping the cat full of O2 and cooling it off. I have also felt a reduction in braking effect as the fuel is added sometimes after a few seconds from getting the revs up as well as when the A/C is turned on when engine braking it will burn more fuel. Just when you think you can cool the car off a little going down hill they squirt in some extra gas anyway!
10-15-2006, 08:03 PM
#118
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I hate Priuses that do 50 f*cking miles per hour on the car pool lane.
I wish I had an F-350 with a snow plow and shove that idiot out of the way.
The selfish bastard maybe getting 40mpg while driving like a turtle, but he's holding back the rest of the world who would like to get to their destination TODAY.
I wish I had an F-350 with a snow plow and shove that idiot out of the way.
The selfish bastard maybe getting 40mpg while driving like a turtle, but he's holding back the rest of the world who would like to get to their destination TODAY.
10-15-2006, 08:37 PM
#119
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Why can't you just pass them? Why criticize other people if they want to drive economically or safely? Highways are designed for people to pass, although I do understand if the HOV lane is enclosed and only one lane - although I've never seen a configuration like that
10-15-2006, 09:39 PM
#120
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Originally Posted by paul34
Why can't you just pass them? Why criticize other people if they want to drive economically or safely? Highways are designed for people to pass, although I do understand if the HOV lane is enclosed and only one lane - although I've never seen a configuration like that
271$ starting fine for crossing the line or not having enough passengers in the car.
excuse him because theres are alot of cali road ragers.