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Discussion Starter · #1 ·
well, i talked to a mechanic at hyundai while i got my oil change and he says he knows what is going on (his wife just got one too ). He said the 2011 hyundai has a smart alternator that charges only during coasting/braking. so the alternator is cut off during acceleration, cruise and re-enables during coast or braking. that way the alternator power comes from power that would have otherwise gone to the brakes. He said doing this way gives about a 10hp advantage during acceleration over not having it this way and gives better mpg during accel or cruise. he said when u coast or apply brakes the car will de-accelerate faster when it kicks in AND also the car will go into higher gear sooner too take more advantage of this by producing higher rpm(??dont understand this). He said this is also done to produce faster response when u do want to accelerate again. He said any loss of coasting ability( and mpg during coast) is more than gained back by doing this method. He said those that are used to using certain methods to gain mpg in other cars like coasting then quickly accelerating then coasting..etc will feel strange at first but will adapt by doing other methods that work better for this car. he said a better method for this car would be to take advantage that the alternator turns off during acceleration/cruise and quickly get to a minimum speed that a certain gear needs to kick in. for instance i believe he said that 5th gear kicks in at around 48 mph. so he said lets say ur at a stop light when it turns green u step on the gas not all the way down but enough that u briskly get to 48 then u back off the accelerator fully and 5 gear will kick in then u reapply gas to maintain 48 mph or even slower but not so slow 4 gear kicks in. he said quickly getting to these shift points and maintaining cruise is better than coasting then accelerating on this car. i tried this method on a 40mph speed limit stretch of road and it defiantly helps. i usually would speed up to 4o slowly(getting about 12mpg on speed up) then stay there (40mph in 4th gear) and get about 35 mpg. now i get to 48 briskly (getting around 6-8 mpg on speed up) but i get to 48mph much much faster than going slowly to 40 (so i guess less time being spent at low mpg's), then i back off, 5th gear hits and i slow to 42 and that gets me about 45mpg instead of 35mpg. im sure this will work with other shifting points. try it out let me know
 

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QUOTE (akalucas @ May 2 2010, 12:09 AM) index.php?act=findpost&pid=318738
well, i talked to a mechanic at hyundai while i got my oil change and he says he knows what is going on (his wife just got one too ). He said the 2011 hyundai has a smart alternator that charges only during coasting/braking. so the alternator is cut off during acceleration, cruise and re-enables during coast or braking. that way the alternator power comes from power that would have otherwise gone to the brakes. He said doing this way gives about a 10hp advantage during acceleration over not having it this way and gives better mpg during accel or cruise. he said when u coast or apply brakes the car will de-accelerate faster when it kicks in AND also the car will go into higher gear sooner too take more advantage of this by producing higher rpm(??dont understand this). He said this is also done to produce faster response when u do want to accelerate again. He said any loss of coasting ability( and mpg during coast) is more than gained back by doing this method. He said those that are used to using certain methods to gain mpg in other cars like coasting then quickly accelerating then coasting..etc will feel strange at first but will adapt by doing other methods that work better for this car. he said a better method for this car would be to take advantage that the alternator turns off during acceleration/cruise and quickly get to a minimum speed that a certain gear needs to kick in. for instance i believe he said that 5th gear kicks in at around 48 mph. so he said lets say ur at a stop light when it turns green u step on the gas not all the way down but enough that u briskly get to 48 then u back off the accelerator fully and 5 gear will kick in then u reapply gas to maintain 48 mph or even slower but not so slow 4 gear kicks in. he said quickly getting to these shift points and maintaining cruise is better than coasting then accelerating on this car. i tried this method on a 40mph speed limit stretch of road and it defiantly helps. i usually would speed up to 4o slowly(getting about 12mpg on speed up) then stay there (40mph in 4th gear) and get about 35 mpg. now i get to 48 briskly (getting around 6-8 mpg on speed up) but i get to 48mph much much faster than going slowly to 40 (so i guess less time being spent at low mpg's), then i back off, 5th gear hits and i slow to 42 and that gets me about 45mpg instead of 35mpg. im sure this will work with other shifting points. try it out let me know
So if you consistently drive on roads where max speed is 35, this car is not designed for you? That's the problem I have. When I drive in areas like that it constantly switches between 5th and 4th gear, which is rather aggrevating. I also find it hard to believe that accelerating quickly is more fuel efficient and better for the engine than slowly pushing the car to a higher speed.

I can appreciate the logic of the engineering, but it would make more sense to have it adaptable to the driving conditions rather than fixed to work best at maintained speeds of 50mph or more. Perhaps I'm just not in the majority though.
 

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Makes sense. It downshifts early to give the rpm's a boost. Power generation is based on RPMs, the higher you have the axial component in the alternator spinning the more power you'll produce.
 

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QUOTE (osrk @ May 2 2010, 04:06 PM) index.php?act=findpost&pid=318890
Makes sense. It downshifts early to give the rpm's a boost. Power generation is based on RPMs, the higher you have the axial component in the alternator spinning the more power you'll produce.
+1. I don't know about the Sonata alternator, but most alternators produce about 20-30 amps at idle and don't produce their designed max (140-160 amps) until 2,500 rpm.
 

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Discussion Starter · #6 ·
QUOTE (SeattleGuy @ May 2 2010, 09:13 AM) index.php?act=findpost&pid=318834
So if you consistently drive on roads where max speed is 35, this car is not designed for you? That's the problem I have. When I drive in areas like that it constantly switches between 5th and 4th gear, which is rather aggrevating. I also find it hard to believe that accelerating quickly is more fuel efficient and better for the engine than slowly pushing the car to a higher speed.

I can appreciate the logic of the engineering, but it would make more sense to have it adaptable to the driving conditions rather than fixed to work best at maintained speeds of 50mph or more. Perhaps I'm just not in the majority though.
I dont think your car is switching to 5 gear going 35mph. the car does not switch to 5th gear until it reach 47-48mph. its prob switching from 3rd to 4th or 4th to 3r gear. what prob happens is that it goes to 4th in 35mph range then because of traffice and what not u slow down to say 33mph and it switches to 3rd...i see how that can be annoying. What i do if i know the flow of traffic is not constant and i know i will be slowing down to a piont the gear might switch lower, I put it in manual shift mode once i hit 4 gear at 35mph and it will stay in that gear much much longer when slowing down.

accelerating briskly (not flooring/not redlining) will do not damage to the engine at all compared to accelerating slowly. like explained earlier, the goal should be to get to the optimal gear and the optimal speed for that gear as briskly as you can. lets say you want to travel 800feet and you do it twice.

one way you get to 800 feet by going really slow up to 45mph (4th gear/35mpg)..going slow gets you 12mpg during acceleration but you get there in 90seconds.
2nd way you get to 800 feet by going rather briskly to 48mph (5th gear kicks in/45mpg) then slow to 45 with 5th gear. going brisk u get 6mpg during accelartion but you there in 45 seconds.

which is faster and saves more fuel. the second one of course because yes you might be spending more fuel to get to 48 going briskly but u get there twice as fast to cruisin than if you u were going slow so u spend less time in accel mode and more time in a gear that wastes less gas. i dont know...maybe im wrong but it makes sense in my mind.

of course if theres stop sign or red light very close by so u wont have a opportunity to cruise for period of time its best to accel slowly..no point in accelerating quickly up to a stop sign that is close by. In this case the car save gas compared to other cars because the alernator turns off when accel which saves about 4-5% in mpg's from what the mechanic told me
 

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QUOTE (akalucas @ May 2 2010, 07:30 PM) index.php?act=findpost&pid=318958
I dont think your car is switching to 5 gear going 35mph. the car does not switch to 5th gear until it reach 47-48mph. its prob switching from 3rd to 4th or 4th to 3r gear. what prob happens is that it goes to 4th in 35mph range then because of traffice and what not u slow down to say 33mph and it switches to 3rd...i see how that can be annoying. What i do if i know the flow of traffic is not constant and i know i will be slowing down to a piont the gear might switch lower, I put it in manual shift mode once i hit 4 gear at 35mph and it will stay in that gear much much longer when slowing down.

accelerating briskly (not flooring/not redlining) will do not damage to the engine at all compared to accelerating slowly. like explained earlier, the goal should be to get to the optimal gear and the optimal speed for that gear as briskly as you can. lets say you want to travel 800feet and you do it twice.

one way you get to 800 feet by going really slow up to 45mph (4th gear/35mpg)..going slow gets you 12mpg during acceleration but you get there in 90seconds.
2nd way you get to 800 feet by going rather briskly to 48mph (5th gear kicks in/45mpg) then slow to 45 with 5th gear. going brisk u get 6mpg during accelartion but you there in 45 seconds.

which is faster and saves more fuel. the second one of course because yes you might be spending more fuel to get to 48 going briskly but u get there twice as fast to cruisin than if you u were going slow so u spend less time in accel mode and more time in a gear that wastes less gas. i dont know...maybe im wrong but it makes sense in my mind.
My physics professor from college would like to have a word with you sir. Something about inertia I think... :wink2:
 

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Discussion Starter · #8 ·
QUOTE (vewdew @ May 2 2010, 05:41 PM) index.php?act=findpost&pid=318962
My physics professor from college would like to have a word with you sir. Something about inertia I think... :wink2:
well, ya, in normal cars you would take advantage of the inertia but like i stated earlier this is in context of the sonata switching on the alternator when its coast/braking and switching off when cruisin or accel. this car is made to take advantage of the inertia and use it to power the battery through the alternator more than others during deceleration, thats why the car slows down more than other cars when you u coast and feel engine braking when applying the brakes. so obviously we cant take advantage of the inertia as much as other cars to raise mpg so i gave some ideas of mine and the mechanics to increase mpg in other ways
 

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I was more referring to your comments about faster acceleration being more fuel efficient. Sir Isaac Newton's laws regarding the relationship between mass, acceleration, and force prove that it is physically impossible for this to be true. Sorry, I'm a nerd. :banana:

Mass = inertia
If you want to accelerate at a higher rate, it requires more force (and thus, more energy/fuel) to overcome inertia. All you're really accomplishing is getting from point A to point B sooner at the cost of more energy.

QUOTE (akalucas @ May 2 2010, 07:53 PM) index.php?act=findpost&pid=318964
well, ya, in normal cars you would take advantage of the inertia but like i stated earlier this is in context of the sonata switching on the alternator when its coast/braking and switching off when cruisin or accel. this car is made to take advantage of the inertia and use it to power the battery through the alternator more than others during deceleration, thats why the car slows down more than other cars when you u coast and feel engine braking when applying the brakes. so obviously we cant take advantage of the inertia as much as other cars to raise mpg so i gave some ideas of mine and the mechanics to increase mpg in other ways
 

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QUOTE (akalucas @ May 2 2010, 05:56 PM) index.php?act=findpost&pid=318965
going to do some real world testing today if i can and post the results
Be careful!

There is a fifth dimension beyond that which is known to man it is a dimension as vast as space and as timeless as infinity it is the middle ground between light and shadow between science and superstition and it lies between the pit of man's fears and the summit of his knowledge this is the dimension of imagination it is an area which we call- the Twilight Zone
 

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Discussion Starter · #13 ·
QUOTE (vewdew @ May 2 2010, 06:57 PM) index.php?act=findpost&pid=318981
I was more referring to your comments about faster acceleration being more fuel efficient. Sir Isaac Newton's laws regarding the relationship between mass, acceleration, and force prove that it is physically impossible for this to be true. Sorry, I'm a nerd. :banana:

Mass = inertia
If you want to accelerate at a higher rate, it requires more force (and thus, more energy/fuel) to overcome inertia. All you're really accomplishing is getting from point A to point B sooner at the cost of more energy.
oh, i see. ok, i was talking about it being more fuel efficient to get faster to a certain gear and speed that is more efficient during a certain disntance than slowly getting to that point and maintaining that point for a certain distance.

for instance, point A to B will signify the distance to reach 45mph with accel times and mpg. point B to C will signify the distance the necessary distance to reach the 800ft in the optimal gear and mpg

A--------slow to [email protected]B([email protected])[email protected] in 4th [email protected](600ft in optimal gear)----------------------------------------------------------------C (800ft end of distance)

compared to:

A------fast to [email protected]B([email protected])[email protected] 5th gear kicks in then slow to 45 maintining 5th [email protected](700ft in optimal gear-----------------------C(800ft end of distance)

so i guess my theory is its best to go faster to the optimal mph to kick in the upshift then going really slow to a certain mph which means spending less time in the optimal cruisin speed. i dont know LOL..going to see tonigh if i can do a real test with vid and post it on youtube to show the decelation of my auto mazda 6 compared to the sonata 2011 auto so you guys can see the big difference then ill do the accel tests on the sonata and see which method produces best mpg. dont have my small digital camera to make the video but only my nikon D90 so waiting for it to get darker here in cali so cops dont see me video recording. not much traffic at all around this time around here so i should be ok
 

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...
..Being new to Hyundai, but not to the automotive repair field most of the other (higher end lines) are now doing multi voltage alternators that only charge when needed and generally never during acceleration. I assume the newer Hyundai's may also.

..... the power required for the on-board network is generated specifically during overrun and during application of the brakes, serving to charge the car's battery at exactly the right time without taking up any of the energy contained in the car's fuel. As long as the engine is "pulling" the car, therefore, the alternator generally remains disengaged. Apart from particularly efficient generation of electric power, this also serves to provide more drive power and traction for supreme acceleration at all times.
 

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Downshifting is good because it run's the alternator at a higher RPM because the engine is turning faster, the belts are turning faster, which means the alternator is turning faster.

Some of you guys must be the jokers that I hate that coast for half a mile to the stop light. **** stupid Hypermilers. I love getting behind you and kicking my train horn on in my truck.
 

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Im glad someone came up with this explanation because it makes perfect sense to me, however, now I have another question.

Since the alternator is engaging and disengaging depending on throttle position, I assume there is some type of "clutch" inside of the alternator (similar to how an A/C Compressor can engage/disengage depending on RPM). But does anyone have any prediction on what type of wear we can expect on the alternator?

A/C Compressors can have clutch failures which snap serpentine belts if they sieze up. It doesnt happen too often because you dont use your A/C all year around (at least not where I live - near Chicago) but your alternator is always being used.

Hopefully this "advanced" alternator isnt increasing failure rate of the alternator, and of course making it more expensive to replace when it does fail.
 

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QUOTE (akalucas @ May 2 2010, 11:00 PM) index.php?act=findpost&pid=318995
oh, i see. ok, i was talking about it being more fuel efficient to get faster to a certain gear and speed that is more efficient during a certain disntance than slowly getting to that point and maintaining that point for a certain distance.
I understand what you're saying and I'm sure vewdew does also. We just don't agree with it. Your theory is counter to everything I've ever read about driving efficiently.
 

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QUOTE (jfulcher @ May 3 2010, 09:31 AM) index.php?act=findpost&pid=319075
Downshifting is good because it run's the alternator at a higher RPM because the engine is turning faster, the belts are turning faster, which means the alternator is turning faster.

Some of you guys must be the jokers that I hate that coast for half a mile to the stop light. **** stupid Hypermilers. I love getting behind you and kicking my train horn on in my truck.

You must be one of **** stupid drivers that I hate, that loves to get up behind me and kick on your train horn cause I'm not going "fast" enough to get to the stoplight so I can jam on my brakes.
 

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QUOTE (akalucas @ May 2 2010, 08:30 PM) index.php?act=findpost&pid=318958
accelerating briskly (not flooring/not redlining) will do not damage to the engine at all compared to accelerating slowly.
What do you mean by this? I know that flooring/red lining the engine will work the engine and obviously in the long run reduce the serviceable lifespan of an engine, but would it literally damage it on the spot? I tend to drive the car more aggressively than the others, and not saying it that I redline it every time, but I do have the tendency to do it more so than others... I wonder if the engine will be bonkers after three years...
 
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