floor it to save gas??
08-06-2006, 11:54 AM
#41
Originally Posted by SlackR237
Easy there, sport.
Yes, it may be running rich, but for a less amount of time, and perhaps that ratio of time (to get to cruising speed) to fuel in WOT is less than time to fuel ratio in slower acceleration. Still, I don't see how that could be easy on the engine.
I'm not saying I'm siding with the WOT theory, I can just see their point.
Yes, it may be running rich, but for a less amount of time, and perhaps that ratio of time (to get to cruising speed) to fuel in WOT is less than time to fuel ratio in slower acceleration. Still, I don't see how that could be easy on the engine.
I'm not saying I'm siding with the WOT theory, I can just see their point.
I nice compromise between reduced pumping losses and excessive fuel being dumped into the motor would be in the 20%-40% throttle range IMO.
08-06-2006, 12:06 PM
#42
Senior Member
Join Date: Feb 2003
Posts: 509
Originally Posted by nismology
Because there is way more load on the motor when you go WOT at low engine speeds than at higher RPM. The motor can't accelerate itself or the drivetrain as quickly at extremely low RPM. This causes the shock of the bigger a/f explosion caused by WOT to be absorbed by the motor. If the piston can't travel downward as fast as the explosion is telling it to, the energy is absorbed by the crank. The main bearings are what hold the crank in place (along with the thrust bearings) so they get stressed more than usual and have a tendency to squeeze the oil out from between them and the main journals. It doesn't help that oil pressure is relatively low at low engine speeds either.
Ask any competent mechanic if lugging the motor is a good idea.
Ask any competent mechanic if lugging the motor is a good idea.
theres a difference between the lugging the engine and using its low end torque, but i guess i do see what you mean about going WOT so low, i dont think its lugging the engine, because it still accelerates pretty quickly, hell i drive around in 4th at 30mph and have no trouble accelerating up to speed from there, then again i dont floor it to either... would the bearings really be weak enough that it could cause damage?
08-06-2006, 12:24 PM
#43
hmmm....as odd as it seems i can see how this might trurly work on paper and in a controlled area such as on a dyno. i'm not to sure how well this would work in the city due to the other traffic which would negate any benifits of doing this due to a lack of room to get up to speed.
just because it sounds crazy doesn't mean it isn't true. we don't really know what our ecu would do. we have lots of assumptions and theories but you just can't say it's impossible.
cliffs: kevlo...u may be wrong
just because it sounds crazy doesn't mean it isn't true. we don't really know what our ecu would do. we have lots of assumptions and theories but you just can't say it's impossible.
cliffs: kevlo...u may be wrong
08-06-2006, 12:25 PM
#44
100% chingon
Join Date: Oct 2005
Posts: 1,003
Originally Posted by nismology
If anyone wants premature wear on their main and rod bearings DO IT. 
The technique mentioned does save fuel. In the UK every year there is a big competition to see who can get the highest fuel economy and going WOT and changing up very early is what they all do, apparently. It's not for me though. I prefer going WOT and waiting for the red line...
08-06-2006, 12:53 PM
#45
Originally Posted by nismology
I think you're misunderstanding the basis of this theory. The point isn't to accelerate faster and thus save gas since you're spending less time accelerating. That's false. The point is to reduce pumping losses by minimizing intake manifold vacuum to improve efficiency. It's true to a point, but you should stay in closed loop mode as much as possible since that's when the ECU tries to maintain an a/f ratio of 14.7:1. Anything past 40% throttle or so and the ECU runs rich.
I nice compromise between reduced pumping losses and excessive fuel being dumped into the motor would be in the 20%-40% throttle range IMO.
I nice compromise between reduced pumping losses and excessive fuel being dumped into the motor would be in the 20%-40% throttle range IMO.
Originally Posted by acidspit86
theres a difference between the lugging the engine and using its low end torque, but i guess i do see what you mean about going WOT so low, i dont think its lugging the engine, because it still accelerates pretty quickly, hell i drive around in 4th at 30mph and have no trouble accelerating up to speed from there, then again i dont floor it to either... would the bearings really be weak enough that it could cause damage?
08-06-2006, 01:04 PM
#46
ill stick to my normal acceleration from a stop. this theory sounds like it needs to be re-examined. after reading what nismology said about putting extra stress on the engine it makes sense.
So is this similar?
for example you can cruise at 60kmh in 5th but the rpms will be around 1500rpm so the on a incline the engine will require more power, so you put your foot farther down untill you have it almost pinned, the rpms are still low 1500rpm but your not really saving fuel because its dumping ****loads in just to maintain 60. But if you were in 2nd or 3rd at the same speed the engine has a lot more power on tap and its in its powerband so it would require less fuel to move the car?
So is this similar?
for example you can cruise at 60kmh in 5th but the rpms will be around 1500rpm so the on a incline the engine will require more power, so you put your foot farther down untill you have it almost pinned, the rpms are still low 1500rpm but your not really saving fuel because its dumping ****loads in just to maintain 60. But if you were in 2nd or 3rd at the same speed the engine has a lot more power on tap and its in its powerband so it would require less fuel to move the car?
08-06-2006, 01:48 PM
#47
Originally Posted by acidspit86
theres a difference between the lugging the engine and using its low end torque, but i guess i do see what you mean about going WOT so low, i dont think its lugging the engine, because it still accelerates pretty quickly, hell i drive around in 4th at 30mph and have no trouble accelerating up to speed from there, then again i dont floor it to either... would the bearings really be weak enough that it could cause damage?
And the bearings are made out of a soft flexible metal so that it doesn't wear into the crank. When you put excessively high load on the motor they flex, which in turn can squeeze the oil film out from between it and the journal.
08-06-2006, 01:51 PM
#48
Originally Posted by MrGone
I may give people too much credit for being able to think on their own but IMHO just drive. If you are heavy on the gas then lighten up. If you take forever to get to 35mph put some more behind it. I call it the happy spot when explaining it to my sisters. It's the point where the motor just goes and you really don't have to do anything. People will probably waste more gas thinking about it then if they just drove normally.
08-06-2006, 06:13 PM
#49
Originally Posted by nismology
That quote makes no sense. You can upshift at low RPM without going WOT.
How does going WOT tie into it? Yup, still pretty retarded. 
How does going WOT tie into it? Yup, still pretty retarded. BTW, it's almost impossible to upshift at low rpms, you MUST accelerate!
08-06-2006, 06:22 PM
#50
Originally Posted by 95bluse
You seem to miss the point. Going WOT & short shifting gets you up to cruising speed faster. Using low rpms takes you longer to get there & you're fighting against friction LONGER, hence more fuel. Take a look around at fuel consumption races, you'll get the idea (hopefully).
BTW, it has to do with pumping losses, not friction. Furthermore, i explained in detail why going WOT at low RPM is no good for the bearings. You go and try it if you'd like.
BTW, it's almost impossible to upshift at low rpms, you MUST accelerate!
08-06-2006, 07:55 PM
#51
Originally Posted by Kevlo911
OMFG you idiots never cease to amaze me. I don't care what bmw does or any other car. THE MAXIMA WOT MAPS ARE RICH. RUNNING RICH WASTES MORE FUEL.
DRIVE NORMALLY LET THE CAR STAY IN CLOSED LOOP SO IT DOES THE OPTIMAL 14:7 AIR FUEL RATIO
DRIVE NORMALLY LET THE CAR STAY IN CLOSED LOOP SO IT DOES THE OPTIMAL 14:7 AIR FUEL RATIO
08-07-2006, 05:40 AM
#54
Originally Posted by 95bluse
You seem to miss the point. Going WOT & short shifting gets you up to cruising speed faster. Using low rpms takes you longer to get there & you're fighting against friction LONGER, hence more fuel. Take a look around at fuel consumption races, you'll get the idea (hopefully).
BTW, it's almost impossible to upshift at low rpms, you MUST accelerate!
BTW, it's almost impossible to upshift at low rpms, you MUST accelerate!
Okay I am back in this thread. Why go WOT, why not accelerate normally?
08-07-2006, 06:42 AM
#55
Originally Posted by Haibert88
i don't understand what you guys mean by "pumping loss"
08-07-2006, 06:49 AM
#56
Originally Posted by Kevlo911
Okay I am back in this thread. Why go WOT, why not accelerate normally?
Because people STILL don't get it that at WOT the ECU runs rich as hell, and closed loop is ALWAYS better then running rich, as you and Nismology have already tried to explain here. Just because a magazine says something, doesn't mean it's going to work for our particular year motors. Most people don't understand how our ECU works anyways, and they like to jump to conclusions based on a magazine article.
Understand folks, these two guys (kevlo911 and Nismology) have lots of first hand experience with the 4th gen ECU. Most of the n00bs on this forum probably don't even know where the ECU is located in our car, or what an ECU IS for that matter.
08-07-2006, 07:14 AM
#58
Originally Posted by GoalieKeg
Because people STILL don't get it that at WOT the ECU runs rich as hell, and closed loop is ALWAYS better then running rich, as you and Nismology have already tried to explain here. Just because a magazine says something, doesn't mean it's going to work for our particular year motors. Most people don't understand how our ECU works anyways, and they like to jump to conclusions based on a magazine article.
Understand folks, these two guys (kevlo911 and Nismology) have lots of first hand experience with the 4th gen ECU. Most of the n00bs on this forum probably don't even know where the ECU is located in our car, or what an ECU IS for that matter.
Understand folks, these two guys (kevlo911 and Nismology) have lots of first hand experience with the 4th gen ECU. Most of the n00bs on this forum probably don't even know where the ECU is located in our car, or what an ECU IS for that matter.
08-07-2006, 07:18 AM
#59
Originally Posted by sgram48
Thats good if you own a manual transmission maxima car. But if you own a automatic is there any way you could save gas. What is the average amount to full up your tank when it near empty?
08-07-2006, 07:40 AM
#60
Originally Posted by NAPhi_Shift
heard about this several times,
only way it makes sense to me logically is taht since your getting your engine up there in your sweet spot, engines are tuned to run at its optimal settings at WOT.
you are getting the MOST efficient use of power, and the engine is at its true working potential. itll get you to speed faster blah blah blah
i dont agree with it though LOL i dont beat on the car when i drive it and have seen considerably better gas mileage. 31mpg highway, holla!
only way it makes sense to me logically is taht since your getting your engine up there in your sweet spot, engines are tuned to run at its optimal settings at WOT.
you are getting the MOST efficient use of power, and the engine is at its true working potential. itll get you to speed faster blah blah blah
i dont agree with it though LOL i dont beat on the car when i drive it and have seen considerably better gas mileage. 31mpg highway, holla!
See post #55 for the definition of pumping losses.
08-07-2006, 07:42 AM
#61
Originally Posted by 95bluse
You seem to miss the point. Going WOT & short shifting gets you up to cruising speed faster. Using low rpms takes you longer to get there & you're fighting against friction LONGER, hence more fuel. Take a look around at fuel consumption races, you'll get the idea (hopefully).
)
08-07-2006, 08:35 AM
#64
Yes, let’s have an experiment; however I believe that it is unlikely that it provides a small (if any) gain in fuel economy,
Even if it provides a “10% increase” it will put more stress on our older cars and end up costing us more in repairs
Even if it provides a “10% increase” it will put more stress on our older cars and end up costing us more in repairs
08-07-2006, 08:38 AM
#65
im not sure if anyone really understands what nismology is saying......
The article says to do this to reduce pumping losses, for those who dont know what this is...
At light application of the gas pedal, the throttle butterfly partially or nearly closes. The pistons are still running and take air from the partially closed intake manifold. The intake manifold between the throttle and the combustion chamber has a partial vacuum, resisting the sucking and pumping action of the pistons, wasting energy. This is pumping loss..... hence the slower the engine runs, the closer the butterfly comes to closing completly, which causes a loss of energy.
keep in mind that this is the purpose of the article
now the point that nismology and kevlo are trying to make is that when you go wot, the ecu goes into open loop mode, which is programmed from the factory to be rich and does not "learn" like ike it does in closed loop mode. when inopen loop the ecu basically dumps gas. The ecu goes into open loop at like 40% throttle, so if you apply between 30-40% throttle you will keep the ecu in closed loop AND reduce pumping losses, Saving gas.
The article says to do this to reduce pumping losses, for those who dont know what this is...
At light application of the gas pedal, the throttle butterfly partially or nearly closes. The pistons are still running and take air from the partially closed intake manifold. The intake manifold between the throttle and the combustion chamber has a partial vacuum, resisting the sucking and pumping action of the pistons, wasting energy. This is pumping loss..... hence the slower the engine runs, the closer the butterfly comes to closing completly, which causes a loss of energy.
keep in mind that this is the purpose of the article
now the point that nismology and kevlo are trying to make is that when you go wot, the ecu goes into open loop mode, which is programmed from the factory to be rich and does not "learn" like ike it does in closed loop mode. when inopen loop the ecu basically dumps gas. The ecu goes into open loop at like 40% throttle, so if you apply between 30-40% throttle you will keep the ecu in closed loop AND reduce pumping losses, Saving gas.
08-07-2006, 08:57 AM
#66
Originally Posted by 97BlackSEGold
im not sure if anyone really understands what nismology is saying......
The article says to do this to reduce pumping losses, for those who dont know what this is...
At light application of the gas pedal, the throttle butterfly partially or nearly closes. The pistons are still running and take air from the partially closed intake manifold. The intake manifold between the throttle and the combustion chamber has a partial vacuum, resisting the sucking and pumping action of the pistons, wasting energy. This is pumping loss..... hence the slower the engine runs, the closer the butterfly comes to closing completly, which causes a loss of energy.
keep in mind that this is the purpose of the article
now the point that nismology and kevlo are trying to make is that when you go wot, the ecu goes into open loop mode, which is programmed from the factory to be rich and does not "learn" like ike it does in closed loop mode. when inopen loop the ecu basically dumps gas. The ecu goes into open loop at like 40% throttle, so if you apply between 30-40% throttle you will keep the ecu in closed loop AND reduce pumping losses, Saving gas.
The article says to do this to reduce pumping losses, for those who dont know what this is...
At light application of the gas pedal, the throttle butterfly partially or nearly closes. The pistons are still running and take air from the partially closed intake manifold. The intake manifold between the throttle and the combustion chamber has a partial vacuum, resisting the sucking and pumping action of the pistons, wasting energy. This is pumping loss..... hence the slower the engine runs, the closer the butterfly comes to closing completly, which causes a loss of energy.
keep in mind that this is the purpose of the article
now the point that nismology and kevlo are trying to make is that when you go wot, the ecu goes into open loop mode, which is programmed from the factory to be rich and does not "learn" like ike it does in closed loop mode. when inopen loop the ecu basically dumps gas. The ecu goes into open loop at like 40% throttle, so if you apply between 30-40% throttle you will keep the ecu in closed loop AND reduce pumping losses, Saving gas.
08-07-2006, 09:50 AM
#67
Originally Posted by 97BlackSEGold
im not sure if anyone really understands what nismology is saying......
The article says to do this to reduce pumping losses, for those who dont know what this is...
At light application of the gas pedal, the throttle butterfly partially or nearly closes. The pistons are still running and take air from the partially closed intake manifold. The intake manifold between the throttle and the combustion chamber has a partial vacuum, resisting the sucking and pumping action of the pistons, wasting energy. This is pumping loss..... hence the slower the engine runs, the closer the butterfly comes to closing completly, which causes a loss of energy.
keep in mind that this is the purpose of the article
now the point that nismology and kevlo are trying to make is that when you go wot, the ecu goes into open loop mode, which is programmed from the factory to be rich and does not "learn" like ike it does in closed loop mode. when inopen loop the ecu basically dumps gas. The ecu goes into open loop at like 40% throttle, so if you apply between 30-40% throttle you will keep the ecu in closed loop AND reduce pumping losses, Saving gas.
The article says to do this to reduce pumping losses, for those who dont know what this is...
At light application of the gas pedal, the throttle butterfly partially or nearly closes. The pistons are still running and take air from the partially closed intake manifold. The intake manifold between the throttle and the combustion chamber has a partial vacuum, resisting the sucking and pumping action of the pistons, wasting energy. This is pumping loss..... hence the slower the engine runs, the closer the butterfly comes to closing completly, which causes a loss of energy.
keep in mind that this is the purpose of the article
now the point that nismology and kevlo are trying to make is that when you go wot, the ecu goes into open loop mode, which is programmed from the factory to be rich and does not "learn" like ike it does in closed loop mode. when inopen loop the ecu basically dumps gas. The ecu goes into open loop at like 40% throttle, so if you apply between 30-40% throttle you will keep the ecu in closed loop AND reduce pumping losses, Saving gas.
/thread
08-07-2006, 02:10 PM
#69
Originally Posted by JSutter
Fighting for peace is like ****ing for virginity
Originally Posted by Kevlo911
ECU maps > you retards
kthxbye
kthxbye
.. yeah I think I'm gonna stop coming to the 4th Gen forum. I see the same damn threads week after week. Or, if they're different they're just plain stupid. I always thought it would end at some point, but actually it just gets worse. Like Fr33way and NMexMax belief that it gets so old and redundant its not worth posting anything intelligent. Half the crowd your teaching (or trying to) can barely harness the english language properly to begin with.
As far as Nismology, that guy fights a hell of a winning battle, props to you.
Back To Lame Topic..
08-07-2006, 08:54 PM
#71
Guest
Posts: n/a
Haha, all this just to save a few bucks.... It makes me laugh that a reputable magazine would even suggest this technique just to save a few bucks. Why ruin the joy of driving, with WOT+Early shifts, just for a few bucks? There are so many better and FUNNER ways to save money on fuel. My personal favorite method:
Ride a bike! (motorcycle)
1 question: What does it mean when the ECU operates in an Open loop? Closed Loop?
Ride a bike! (motorcycle)
1 question: What does it mean when the ECU operates in an Open loop? Closed Loop?
08-08-2006, 06:17 PM
#72
Senior Member
Join Date: Nov 2000
Posts: 467
This concept actually goes back decades to the last oil crisis during the Jimmy Carter as president years. Only a few cars had real fuel injection back then, so someone came up with the concept, tried it, and it worked well. As explained earlier, fuel injection doesn't just pump gas into the cylinders when you romp it like a carburator does. By opening the throttle all the way quickly, you are reducing what they call pumping losses, and the engine breathes much better. If you let it spin up to a high RPM, it will burn more gas, but by keeping the RPM low (early shifting), you do stand the chance of burning much less gas. Of course, you won't get the pleasure of running the engine up with all the $$ you've spent making it run fast, but it should help the mileage. Bottom line...this is not new news...the car magazines are just reprinting what they've covered almost 25-30 years ago...and it should work.
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