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Re: Hypermilers - Post SAFE High FE Driving Tips
I have noticed the same results with my Prius. The first week we had the car, I noticed that whether you accelerate gently or hard, the fuel economy is about the same.
Just for fun last weekend, I 'borrowed' our Prius from my wife to go somewhere, and drove about 22 miles round trip. I practically floored the car from each traffic light or stop sign until I reached the desired speed. I did not change any of my other driving habits (I do as much coasting as traffic safely permits). The results? 64mpg. We have a HCH2, and the same technique does not work with the Honda. Most people I have mentioned this 'trick' to don't believe it, so it will have to be our little sectret. Happy hypermiling! |
Re: Hypermilers - Post SAFE High FE Driving Tips
Well, I sincerely hope our inference is correct and is verified by some other data points .. anyone else tried this??
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Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by GeekGal
This was posted here on GreenHybrid a couple months' back:
http://www.officer.com/article/artic...on=19&id=27281 |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by ppgroup
I have noticed the same results with my Prius. The first week we had the car, I noticed that whether you accelerate gently or hard, the fuel economy is about the same.
[...] Most people I have mentioned this 'trick' to don't believe it, so it will have to be our little secret. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by ppgroup
We have a HCH2, and the same technique does not work with the Honda.
Most people I have mentioned this 'trick' to don't believe it, so it will have to be our little sectret. Happy hypermiling! |
Re: Hypermilers - Post SAFE High FE Driving Tips
That's funny because that technique seems to more or less work in the Insight. I don't "floor it", but I accelerate fairly quickly. Maybe I will do some comparisons, but my perception in the past was, a short burst of low MPG w/high assist and then maintaining speed worked better than a longer burst of higher (but still low due to acceleration) MPG and then the same. Maybe it has something to do with the Insight's lightness and the fact it only has a 3 cylinder engine. Maybe the electrical assist adds more assist in comparison to engine output. Also, as the CVT systems in the Honda Hybrids tend to kick in more IMA assist to "hold" the engine in that efficient range as long as possible, the effect is even greater - you get the maximum power available at the optimum RPM + lots of electric boost. The HCH-II drive-by-wire system probably already automatically incorporates this technique even at lower throttle settings moreso than the Insight/HCH-I, and opening it up more may have the trigger the less efficient set of cams (new on HCH-II) to generate more power. |
Re: Hypermilers - Post SAFE High FE Driving Tips
WOT does not give optimum gas savings. From all the stuff I have seen, gentle acceleration is best.
One thing people forget when they figure on hard acceleration is that they may get to a speed they don't have to get to and have to use the brakes more which takes away any gains. I recomend acceleration rates of slowly applied throttle up to around 1900 rpms (I wouldn't even go that high if I don't have traffic behind me) |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by tbaleno
WOT does not give optimum gas savings. From all the stuff I have seen, gentle acceleration is best.
One thing people forget when they figure on hard acceleration is that they may get to a speed they don't have to get to and have to use the brakes more which takes away any gains. |
Re: Hypermilers - Post SAFE High FE Driving Tips
My shift points are in the range of 2000RPM under moderate (50-65%) load. While cruising is the most efficient state for the car, it is impossible to make up for a very inefficient (in my case 10-20mpg) start with a few hundred extra feet of cruising. Remember that you can't un-burn that fuel, only average it out slowly.
As far as pumping losses are concerned, I think that's really the wrong way to look at it. Going WOT for a few seconds may be a more efficient way to produce power, but that doesn't mean that you are using the extra power efficiently. In addition to paying for the kinetic energy gained, you also have to pay for significantly increased drivetrain losses if you end up at high RPM (a factor especially for automatic and CVT-equipped cars) and slightly more aero drag due to slightly more distance travelled at high speed. Finally, many vehicles run rich at WOT under open-loop fuel management in order to protect the engine from pinging and detonation, which is akin to dumping fuel directly out your tailpipe. So I don't think there's anything to be gained except thrills, engine wear, and two seconds off of your trip time. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by brick
My shift points are in the range of 2000RPM under moderate (50-65%) load. While cruising is the most efficient state for the car, it is impossible to make up for a very inefficient (in my case 10-20mpg) start with a few hundred extra feet of cruising. Remember that you can't un-burn that fuel, only average it out slowly.
As far as pumping losses are concerned, I think that's really the wrong way to look at it. Going WOT for a few seconds may be a more efficient way to produce power, but that doesn't mean that you are using the extra power efficiently. In addition to paying for the kinetic energy gained, you also have to pay for significantly increased drivetrain losses if you end up at high RPM (a factor especially for automatic and CVT-equipped cars) and slightly more aero drag due to slightly more distance travelled at high speed. It's also true that average speed will be slightly higher, leading to slightly more drag. If I wanted to nitpick I suppose you could compare accelerating at a slower rate to a slightly faster top speed, so that you'd end up at the same overall average speed, for the sake of comparison ;) Finally, many vehicles run rich at WOT under open-loop fuel management in order to protect the engine from pinging and detonation, which is akin to dumping fuel directly out your tailpipe. So I don't think there's anything to be gained except thrills, engine wear, and two seconds off of your trip time. The only other case where I'd say it's more efficient overall to accelerate as fast as possible is if accelerating more slowly would impede traffic behind me and reduce their fuel efficiency. For example, if I am the only car in my lane stopped at a traffic light that has just turned green, with traffic at full-speed approaching me, acclerating very rapidly will mean that all those cars behind me can simply maintain their speed. Accelerating at a slower rate, would force them to slow down more, then re-accelerate -- a huge amount of fuel when multiplied across several larger vehicles, though I personally don't see any of those savings, it is a reduction in overall emissions. |
Re: Hypermilers - Post SAFE High FE Driving Tips
The other thing to consider (that I have ignored completely) is how the electric part of the hybrid drivetrain kicks in for these new-fangled xxH cars. I have to assume that the amount of battery power used is somehow related to throttle input. My understanding is that a Prius uses electric-only if it can, then supplements with gasoline power. But I've read that a HCH does the oppisite, starting off on gasoline power and then supplementing with electricity if the driver demands faster acceleration. Does that sound right?
If so, I imagine that you could run into a situation with something like an HCH where too little throttle input means less electric assist than would be optimal. This might put you in a situation where you take off less efficiently at low load than you would if you just got into it a little more and used some of the energy that you regenerated at the last stop. Maybe? Maybe not? |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by brick
If so, I imagine that you could run into a situation with something like an HCH where too little throttle input means less electric assist than would be optimal. This might put you in a situation where you take off less efficiently at low load than you would if you just got into it a little more and used some of the energy that you regenerated at the last stop. Maybe? Maybe not?
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Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by HyChi
Tarabell at CleanMPG has kind of determined that 1900 rpm is the optimal rate for mpg during acceleration.
However, another thing to consider about the assist, is that although the rate of elecrtic assist may be lower for a more gradual acceleration, the total amount of elecrtic energy added to accelerate to 60mph is probably fairly close for both styles of acceleration, as assist seems to be added more or less in proportion to engine power. (Longer acceleratins would have a less powerful assist, but over a longer time) Having some sort of independent control over this would allow for improvement, though, seeing as the driver could predict when an opportunity would be available to recharge again. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Hey, what about Prius acceleration? What technique is better for pulsing? Is faster acceleration or slower acceleration better during pulsing?
Double Trinity mentioned "Well, the comparison has to do with accelerating rapidly up to the same given speed, all else equal after that point." I think, the comparison is not to accelerate to the same given speed, rather the comparison is on the fuel consumed for the same distance covered - say for a whole trip? What would give you a better MPG? A faster acceleration during the pulse phase or a slower acceleration during the pulse phase. The glide phase in both the different techniques is the same. Priuschat.com has an article explaining the methodology of P&G. And they also have a formula for the distance that one needs to glide after having covered certain distance with a certain average MPG number to obtain an overall target MPG number. So, I guess, if someone did really bad on their average MPG numbers during pulsing, they would have to glide for a longer time to achieve their target mpg... That would mean slowing down on the glide phase to a really slow speed .. what if I dont want to do that? And I want to stay within the 30-40 range. Consider an open road, and not traffic trailing behind me .. Should I accelerate faster from 30 to 40 MPH and then glide back to 30 MPH - repeat - OR - accelerate slower from 30-40 MPH and glide and repeat?? The time factor might be significantly different between the two techniques for a given trip, if the trip is considerably long one .. but I want to get some views on the fuel savings if any? In my limited experiements (600 miles on Prius), I seem to be getting about the same MPG numbers whether I push for a little harder accelerations or go for slower (granny-type .... hmm .. may be a little facter than that ..) accelerations .. Any comments?? Cheers! |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by tomdavie
(Post 66332)
gang
thanks for the new info regarding the tire pressure. I will bump mine up to 3 psi below max sidewall. That seems reasonalbe. NOT to what some of these jokers bump it up to however. i will NOT bring apparatus in my car like wet towels and ice just so i dont put the AC on. I will NOT spend my waking hours obsessed with being able to post the best MPG on this site or lose sight of the fact it ALREADY gets much better mileage than a regular gas car. Can we just get on with our lives without going way overboard? To the casual observer, going crazy on the MPG to the point of where it starts to really look ridiculous actually cheapens the site as average folks cant relate to it, and conclude we are a 'fringe group' of obsessed freaks. My hope was to promote the benefits of the hybrid, as a normal american would enjoy it, so that more and more of us will switch to hybrids. I didnt come here to become part of some cult that goes to ridiculous lengths to embellish MPG to the point where nothing else in life matters. Boasting MPG numbers that are 'dubious' at best, obscure scenerios, and outright bragging about ridiculous technics does not help our cause. Its done to showcase the egos of those involved -which saddens me Helium in the tires???? cmon man.......... Automakers no doubt read our blog , eagerly seeking what the real world MPG is on their vehicles. They end up having to take it with a 'large margin' grain of salt when they see the ridiculous lengths these guys go to to 'put up numbers' like its a contest or something. They are not interested in obscure scenerio trumped up numbers that wont be realistically duplicated in normal situation driving. Do you honestly believe toyota or honda is going to start handing out wet towels and ice -instead of AC -on their cars. Not very constructive a suggestion huh...... Even if the 'technics' can be taught, americans are not going to spend all this time 'relearing' how to drive to milk an extra mpg out of their car, and if they do -they will just use the new skills in their gas cars, defeating the purpose of driving a hybrid, as their 'state of the art' training will reap them better mileage in their gas cars. So why shell out the extra expense of the hybrid? Do you now honestly expect honda and toyota to now include classes on how to 'pulse and glide' -instead of just drive the **** car? Average americans come to this site , looking to get better mpg , and help the enviroment and foreign oil. They then are aghast to see hybrid drivers talking some 'funky' language about wholesale changes in driving and tire pressure and all this crap -when all they wanna do is buy a new car. Didnt we purchase the hybrid for the enviroment? We all know the price was trumped up so that we have to drive about 100k miles to make up the diff in gas savings. Automakers , nor consumers can take these overinflated numbers seriously as what an average consumer would do. I guess im asking for too much for all of us just to drive the **** things and report what we get as 'real world' without all the ego feeding ridiculous gyrations. There are good common sense suggestions here to help the MPG slightly. However, there is also a bunch of nonsense and ego feeding going on that is turning off americans from buying a hybrid. This cheapens the site and takes away from the benefits that are here. just my .02. srry for the rant -it has been building up for some time now. I was behind ones of these clowns at 05.30 this morning on I-10 west in his HCH 2, complete with the antagonistic vanity plate... cuz, you know, the badging just isn't enough, doing a solid 20 mph UNDER the prevailing flow of traffic in the #3 lane. Look, I dig the passion.... to a point but this guy was a danger to others around him and frankly, I was momentarily flushed with the urge to slap him silly... but I was too busy worrying about the crush of traffic piling up behind me. |
Re: Hypermilers - Post SAFE High FE Driving Tips
<<<Didnt we purchase the hybrid for the enviroment? We all know the price was trumped up so that we have to drive about 100k miles to make up the diff in gas savings.>>>
In two and a half years I will realize a cost savings in purchasing a Saturn Hybrid Vue over a regular Vue (I have calculated my breakeven point at 65,000 miles with a $3.00 a gallon average.) As for taking mpg to the extreme, I speed along at 70-75 mpg and use the A/C where necessary. You would not be able to tell that I was driving a Hybrid if it wasn't for the small Hybrid tag my trunk. Getting great gas mileage, reporting the numbers honestly and driving with the flow of traffic - that is what makes this "Hypermiler" happy. :D |
Re: Hypermilers - Post SAFE High FE Driving Tips
I would not recommend that kind of driving in rush hour traffic...I get the distinct impression that the occurance of this kind of thing is greatly exaggerated.
All I can add is I was an aggressive driver five years ago and steadily gone to the hypermiling side without being an obstruction like this guy on I10. Several corllaries to "Just Drive it" - "Just Spend it", "Just Eat It"....ever notice that important things like a job, finances, health, involve some thought rather than go thru the motions like a zombie? ;) A few people are really angered by that concept.
Originally Posted by McGyver
(Post 131318)
~AMEN MY BROTHER~ TESTIFY!
I was behind ones of these clowns at 05.30 this morning on I-10 west in his HCH 2, complete with the antagonistic vanity plate... cuz, you know, the badging just isn't enough, doing a solid 20 mph UNDER the prevailing flow of traffic in the #3 lane. Look, I dig the passion.... to a point but this guy was a danger to others around him and frankly, I was momentarily flushed with the urge to slap him silly... but I was too busy worrying about the crush of traffic piling up behind me. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Driving 20 under the flow in the center lanes isn't a good idea anywhere or any time. Are you sure they weren't having mechanical problems? I've seen friends autos loose power before and they get so busy trying to find out what's wrong they get distracted from the road.
As a teen, the brakes of a friend of mine went out, pushed all the way to the floor and he froze- sending us across a busy intersection. I was telling him to "Pump the brakes, pump the brakes" but he was just froze in fear. Two days ago a tire on an old Bronco I was behind exploded. It fell to the rim with a shower of sparks. I had enough room to avoid the flying parts but the driver, obviously distressed kept going for some time before pulling over. Since a person driving 20 under in the center lanes won't last long, I'd tend to believe mechanical trouble rather than pinning a shameful tag of hypermiler with an urge to slap... On the other hand I've had my time lately with slow drivers on single lane roads. Obviously trying to drive more efficiently but lacking any knowledge in the matter is only causing problems. For example riding brakes down hill to maintain under the speed limit while me and 12 cars are in parade. I wouldn't call these slow drivers "Hypermilers" but rather ignorant. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by McGyver
(Post 131318)
~AMEN MY BROTHER~ TESTIFY!
I was behind ones of these clowns at 05.30 this morning on I-10 west in his HCH 2, complete with the antagonistic vanity plate... cuz, you know, the badging just isn't enough, doing a solid 20 mph UNDER the prevailing flow of traffic in the #3 lane. Look, I dig the passion.... to a point but this guy was a danger to others around him and frankly, I was momentarily flushed with the urge to slap him silly... but I was too busy worrying about the crush of traffic piling up behind me. you may be fairly new to this site, perhaps not. however, your antagonistic attitude of wanting to slap someone sillly doesn't exactly endear you to anyone, except perhaps the other poster who agrees with you. that type of anger is a large part of what's wrong with driving today, aside from high gas prices. was this driver going 20 under the speed limit, or 20 under what all the speeders have decided should be the norm? when did speeding become legal or safe, for that matter? the fact that the "norm" may be 20 miles over the posted limit does not necessarily mean that everyone in that conga line has the reflexes to stop should someone up the line have a blowout.....or a deer runs into the road....or someone loses control. how about getting fried about the blatant disregard for speed laws and safety demonstrated on a daily basis by people who think they just have to be there (wherever) before anyone else. how about people who roar up behind you and attempt to squeeze into the passing lane with a foot to spare because they don't want to be bothered to disengage the cruise control? or the ones who switch from lane to lane at high speed in the hopes of getting where, to work an extra 30 seconds earlier? i drive a 65MPH rural 4 lane to work on a daily basis.i am within the law when i drive 60 in the far right lane. and boo hoo if you had one day that you had to slow down for some reason. get over it. the day is coming when we will all have to slow down, or we're going to just plain not be able to afford the stuff. if you don't want to do what you can to reduce your usage, fine. but to come onto a site and call those who do clowns to me shows how little you really care about the whole issue. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by Hot_Georgia_2004
(Post 66140)
10. If your car sits parked for hours then back it in, so when you return you don't have to back it out, put in D and go. This way when you return you can just put in D and go.
Stephen |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by scm2000
(Post 134001)
Can you explain a little more about this one? When you back a cold car out of a spot its done on electric power, probably before the engine starts for its warmup. (talking about a Prius here). Seems to use the same amount of energy as, passing the spot, and then backing it in to park it.
Bob Wilson |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by bwilson4web
(Post 134012)
At startup, the backup requires at least two starts from a dead stop. However, startup with a straight pull-out avoids one full stop. Unfortunately, the ICE is running in an inefficient state so starting from a stop is especially energy expensive.
Bob Wilson Pulling straight in and backing out uses 2 starts from a dead stop, both on leaving. backing in uses 2 starts from a dead stop, one when going into reverse from a stop after passing the spot, the other when you leave. Stephen |
Re: Hypermilers - Post SAFE High FE Driving Tips
I think backing in has the potential to be more beneficial in the HCH (what Hot Georgia drives) than the Prius. However, it can still be beneficial in the Prius. If you do not back in, there is a greater chance that your ICE will start while you are not moving forward and are in EV mode. This is not good use of the ICE in regards to fuel economy. I think the best case scenario is that when your ICE does start, it is at least being used to propel the car.
Of course, if backing in takes you more time and attempts than pulling in face first, the benefits may be lost. This could happen if you are backing into a tight spot. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by scm2000
(Post 134034)
Backing up does not use the ICE. If you are talking about the ICE warmup, it was going to do that anyway. and besides, the backing up is complete before the ICE starts for warm up.
Pulling straight in and backing out uses 2 starts from a dead stop, both on leaving. backing in uses 2 starts from a dead stop, one when going into reverse from a stop after passing the spot, the other when you leave. From memory, I'm seeing the ICE initially run very rich with a throttle airflow rate at ~4.5 grams/sec to warm-up and light-off the ICE. Within the first minute, this drops down to about 3.1-3.5 grams/sec and eventually down to 2 grams/sec just before it is warm enough to begin hybrid operation. It is during this first minute of very rich, warm-up that back-out versus pull-out has an advantage. Once the car is warmed up, at the end of a trip, it is not an issue. BTW, back-in is dependent upon safety. We have a 75 ft driveway and backing in from the street is a challenge. So often, I'm backing out in the morning, which isn't much better. But at work, I can easily back into my parking space. Without a backup camera, I like the improved view when pulling out. In the morning, I typically start the ICE which runs very rich, +4 g/s, without the vehicle moving. I put the car in reverse and it does shutdown the ICE once I'm going ~5 mph or faster. If I creep out, the ICE remains running. Once I reach the street and brake, the ICE starts up again, in the +4 g/s burn rate. The following chart shows what I mean: http://hiwaay.net/%7Ebzwilson/prius/pri_neutral_01.jpg The next mile is driven through the neighborhood at speeds ~25 mph with maximum use of "N". In "D", the ICE burn rate during warm-up is significantly higher than in "N" at the same speeds. There is no accelerator 'feathering' that can mitigate this extra fuel burn. It appears to be a load on the ICE by MG1/MG2 to accelerate warm-up. Pull-out parking is not a universal solution versus ordinary backup. It is most effective when the ICE is stone cold but certainly safety comes first. Individual terrain and patterns can often make backing out a better answer. Bob Wilson |
Re: Hypermilers - Post SAFE High FE Driving Tips
Always run your ac fan at the lowest comfortable level after cool down.
Always set your temp. to the highest comfortable level. Only use your headlights when required. 1. The air will be colder as the fan is not heating up the coils as fast. 2. The draw on the battery will be less with slow fan speed. 3. The ac compresor will cycle on and off if the system hits the low level cut off reducing eng. drag and battery draw. If running heat also use low fan speed and only use defrost when needed. Hope this helps. 08 FEH |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by Nward
(Post 134811)
Only use your headlights when required. |
Re: Hypermilers - Post SAFE High FE Driving Tips
I own the TCH so this might not apply to you. However, I have noticed that I consistently get at least 42 mpg on my daily trips to and from work. The following is my strategy:
(1) I accelerate to 40 mph with the instant mpg meter at 20mpg. After 40 mph I slowly back my foot off the pedal till the instant mpg meter is at 30 - 40 mpg(Do this wisely!! If you are approaching an upward hill, keep up the pressure to maintain speed at minimum), do not impede with traffic! This means do this on the far right lane. I continue to my desired speed which is typically 70 - 80 mph. (2) At this point I am @ 80mph and the instant mpg meter is most likely @ 40mpg. I gradually back off (I do not fear losing speed at this point, because the limit on NJ Turnpike is usually between 55 and 65mph) the accelerator and watch the instant mpg meter go up to 50mpg. I stay at 50mpg for as long as the car stays above 65 mph. If I feel it trying to drop below 65mph, I depress the accelerator gently till I reach a position that maintains that speed and back off accordingly until I reach 50 mpg. I never let the meter go all the way to 60 mpg (too little power most of the time) and try to keep it between 45 mpg and 55 mpg. (3) If you are in a city setting, do not accelerate to stop lights!!! It is dangerous and a waste of gas!! Let the vehicle coast for as long as you can. If possible, accelerate to 40 mph briskly and let go of the accelerator and watch the car get into EV mode (depends on SOC of battery). Try to maintain this speed in EV mode for as long as you can and watch your FE rise!!! |
Re: Hypermilers - Post SAFE High FE Driving Tips
The more the draw on the battery the less mpg you will get.
If you use the ac try to get it to cycle the compresser on and off. If coasting turn the ac to max if you need more cool air. When pulling up a hill just use the fan not ac. These tips will only give a small increase in mpg (1-2) but they are safe and easy. When pulling up a hill use your foot not cc and try not to increase the pressure on the gas. You will slow down but going down you will increase speed and mpg. Hope this helps. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by chiedoziedike
(Post 134933)
I own the TCH so this might not apply to you. However, I have noticed that I consistently get at least 42 mpg on my daily trips to and from work. The following is my strategy:
(1) I accelerate to 40 mph with the instant mpg meter at 20mpg. After 40 mph I slowly back my foot off the pedal till the instant mpg meter is at 30 - 40 mpg(Do this wisely!! If you are approaching an upward hill, keep up the pressure to maintain speed at minimum), do not impede with traffic! This means do this on the far right lane. I continue to my desired speed which is typically 70 - 80 mph. (2) At this point I am @ 80mph and the instant mpg meter is most likely @ 40mpg. I gradually back off (I do not fear losing speed at this point, because the limit on NJ Turnpike is usually between 55 and 65mph) the accelerator and watch the instant mpg meter go up to 50mpg. I stay at 50mpg for as long as the car stays above 65 mph. If I feel it trying to drop below 65mph, I depress the accelerator gently till I reach a position that maintains that speed and back off accordingly until I reach 50 mpg. I never let the meter go all the way to 60 mpg (too little power most of the time) and try to keep it between 45 mpg and 55 mpg. (3) If you are in a city setting, do not accelerate to stop lights!!! It is dangerous and a waste of gas!! Let the vehicle coast for as long as you can. If possible, accelerate to 40 mph briskly and let go of the accelerator and watch the car get into EV mode (depends on SOC of battery). Try to maintain this speed in EV mode for as long as you can and watch your FE rise!!! deleting my post about speeding... |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by scm2000
(Post 134969)
deleting my post about speeding...
What did you say in your post???? |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by chiedoziedike
(Post 134933)
I own the TCH so this might not apply to you. However, I have noticed that I consistently get at least 42 mpg on my daily trips to and from work. The following is my strategy:
(1) I accelerate to 40 mph with the instant mpg meter at 20mpg. After 40 mph I slowly back my foot off the pedal till the instant mpg meter is at 30 - 40 mpg(Do this wisely!! If you are approaching an upward hill, keep up the pressure to maintain speed at minimum), do not impede with traffic! This means do this on the far right lane. I continue to my desired speed which is typically 70 - 80 mph. (2) At this point I am @ 80mph and the instant mpg meter is most likely @ 40mpg. I gradually back off (I do not fear losing speed at this point, because the limit on NJ Turnpike is usually between 55 and 65mph) the accelerator and watch the instant mpg meter go up to 50mpg. I stay at 50mpg for as long as the car stays above 65 mph. If I feel it trying to drop below 65mph, I depress the accelerator gently till I reach a position that maintains that speed and back off accordingly until I reach 50 mpg. I never let the meter go all the way to 60 mpg (too little power most of the time) and try to keep it between 45 mpg and 55 mpg. How did you deterrmine that this is: (a) safe (or is it just the Lemming Principle?) (b) fuel efficient (is the TCH somehow exempt from the laws of physics, specifically aerodynamics?) You're certainly free to do whatever you want but it does seem a bit odd to post this here. |
Re: Hypermilers - Post SAFE High FE Driving Tips
FYI John, I do not recommend speeding. If you read my post carefully you will notice that I also recommended losing speed gradually till you get back to the limit recommended by law (65mph). The main reason I suggest getting up to that speed is to calm "angry" motorists down for a while so that when you start losing speed they simply move to another lane without trying to harass you. Most of the time people zoom past me - even at 80 mph. When I get down to 65 mph, they are continuously zooming past me, cars, trucks, buses...you name it.
It is a well known fact that most drivers out there don't drive at the designated speed limit. My comment is to make it clear that you don't need to drive below speed limit (and endanger your precious life) to achieve high FE. Also, using CC might not be the best way either cos' it demands too much power going uphill and I just don't like entrusting my life to a computer...(I know the car is a "computer", but I like to take control of what I can). I've driven on roads with posted speed limits of 55mph. and had people honking hysterically behind me just because I was doing 60mph. I don't recommend speeding because it is unsafe and impractical (doing speeds over 80mph just burns gas faster without an equivalent rise in power output). If you feel the need to do 20 mph below the limit just to achieve a 2% rise in FE and risk your life...be my guest. I just won't take such chances with so many impatient people out there. My $.02 |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by chiedoziedike
(Post 135179)
FYI John, I do not recommend speeding. If you read my post carefully you will notice that I also recommended losing speed gradually till you get back to the limit recommended by law (65mph). The main reason I suggest getting up to that speed is to calm "angry" motorists down for a while so that when you start losing speed they simply move to another lane without trying to harass you. Most of the time people zoom past me - even at 80 mph. When I get down to 65 mph, they are continuously zooming past me, cars, trucks, buses...you name it.
It is a well known fact that most drivers out there don't drive at the designated speed limit. My comment is to make it clear that you don't need to drive below speed limit (and endanger your precious life) to achieve high FE. Also, using CC might not be the best way either cos' it demands too much power going uphill and I just don't like entrusting my life to a computer...(I know the car is a "computer", but I like to take control of what I can). I've driven on roads with posted speed limits of 55mph. and had people honking hysterically behind me just because I was doing 60mph. I don't recommend speeding because it is unsafe and impractical (doing speeds over 80mph just burns gas faster without an equivalent rise in power output). If you feel the need to do 20 mph below the limit just to achieve a 2% rise in FE and risk your life...be my guest. I just won't take such chances with so many impatient people out there. My $.02 You certainly did advocate speeding by saying you get better FE by accellerating to 80 mph in a 55-65mph zone, that is at least 15mph over the limit. Not only that, you do it in a dangerous way, that is, you are either accellerating or decellerating, not driving a constant speed as all of the other traffic is likely doing. As for driving 20 below the limit, I would never drive below the speed limit on a highway, that is nuts. You don't need to. 50-55mpg at 55mph (in my case, according to the bar graph on the MFD) is pleanty. If someone is honking hysterically at you and putting you in danger because you are doing 60, the safest thing to do would be to let them pass and get them out of your life, because they are unstable, certainly do not speed up and keep them behind you where they can continue to put you in danger. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by chiedoziedike
(Post 135179)
If you feel the need to do 20 mph below the limit just to achieve a 2% rise in FE and risk your life...be my guest. I just won't take such chances with so many impatient people out there.
https://www.greenhybrid.com/discuss/...-fe.14566.html His data shows 42mpg at 70mph (like you) and 65mpg at 55mph, a difference of 54%, not 2%. And he's NOT going 20mph under the speed limit. Do some testing and see what you get. As for driving under the upper speed limit (the speed limit on I-95 here is 65max, 40min, so anything between is legal), I do it all the time (a year of commuting so far) and do not have problems. Generally 50-55mph. I agree that slower than 50mph people who aren't paying attention may not react quickly. Quite often (like yesterday) someone settles in a safe distance behind me and stays there for miles. I tried going 65 and, as you and scm2000 note, everyone passes you anyway. Before you condemn this practice you should try it for a while. Ease into it by starting with speed limit for a week, then 5 under, etc, so you get used to people passing you. I was a bit nervous at first but got over it. Stay a bit to the right side of the right lane so they get a hint. Use hazard flashers for speeding trucks when they are well back to help them change lanes and whiz by. Let anyone merging on come in ahead of you. Monitor traffic in your mirrors and if the road is empty behind you, do whatever you want until the next clump catches you. I think you will find that it is not as dangerous as you think it is, and that as long as you drive in a predictable way you won't get molested. I agree with scm2000 that the best way to deal with wackos is to help them by rather than spend time around them. But hey if this is too scary for you then don't do it. Basically what you are doing is driving with load: constant load (mpg) on the engine rather than constant speed, which cruise control would do. Nothing wrong with that, it helps FE. Doing the same thing at lower speeds would yield higher FE. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Another consideration for highways is truck speed limits.
Often the truck limit is say 5-10mph lower than for other vehicles. I tend to run 60 in a 65 where truck limit is 55mph. Guess what, the trucks tend to run 60 anyhow, so they keep pace with me and provide a decent wind block :) Yep, the test verified what I thought - anything over 60mph and my HCH2 FE nosedives. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by lightfoot
(Post 135199)
Take look at this thread:
https://www.greenhybrid.com/discuss/...-fe.14566.html His data shows 42mpg at 70mph (like you) and 65mpg at 55mph, a difference of 54%, not 2%. And he's NOT going 20mph under the speed limit. Do some testing and see what you get. As for driving under the upper speed limit (the speed limit on I-95 here is 65max, 40min, so anything between is legal), I do it all the time (a year of commuting so far) and do not have problems. Generally 50-55mph. I agree that slower than 50mph people who aren't paying attention may not react quickly. Quite often (like yesterday) someone settles in a safe distance behind me and stays there for miles. I tried going 65 and, as you and scm2000 note, everyone passes you anyway. Before you condemn this practice you should try it for a while. Ease into it by starting with speed limit for a week, then 5 under, etc, so you get used to people passing you. I was a bit nervous at first but got over it. Stay a bit to the right side of the right lane so they get a hint. Use hazard flashers for speeding trucks when they are well back to help them change lanes and whiz by. Let anyone merging on come in ahead of you. Monitor traffic in your mirrors and if the road is empty behind you, do whatever you want until the next clump catches you. I think you will find that it is not as dangerous as you think it is, and that as long as you drive in a predictable way you won't get molested. I agree with scm2000 that the best way to deal with wackos is to help them by rather than spend time around them. But hey if this is too scary for you then don't do it. Basically what you are doing is driving with load: constant load (mpg) on the engine rather than constant speed, which cruise control would do. Nothing wrong with that, it helps FE. Doing the same thing at lower speeds would yield higher FE. Your "apples to oranges" comparison sheds more light to the fact that you do not know what you are talking about. In all honesty, driving the TCH at 50-55 mph based on my experience tends to yield about 47-50mpg. At 65-70mph it tends to yield me about 42-45mpg. A considerable rise in FE (about 11 % if you take the upper limits), but nothing close to 54%. My daily commute is 55miles one way and I would not consider doing 55mph on the turnpike, unless if it is slowed by traffic (or speed limitations) or other adverse weather conditions. It would just take me too long to get there and my body would take an unnecessary hit daily(I already get up early enough to make it there). spartybrutus: Trucks don't drive at the posted limit....maybe in your state but not in NJ. They drive at speeds of 70 mph and up. scm2000: You still don't understand my post and I don't feel like explaining myself anymore. I am glad you enjoy your Prius, but your comment is sort of porous. How could you claim you get better than EPA estimates if you are only getting 50-55mpg ...Let me remind you that the OLD EPA estimate for the Prius is 60mpg. As for the TCH, the OLD EPA estimate is 40mpg....I am not trying to knock your car or act like I know it all. You have your techniques, I have mine. I still can't find any of your posts contributing to this thread, instead, your goal has been to deride my comments. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by chiedoziedike
(Post 135282)
Lightfoot: I know you are a very intelligent man/woman.
Originally Posted by chiedoziedike
(Post 135282)
However, I don't think the difference in FE while driving a TCH at those said speeds would be as high as 54%. Please take note that the vehicle mentioned in the article is a HCH2. The best FE I've heard of on a TCH (full tank that is) is about 51mpg (800 mile tank).
Originally Posted by chiedoziedike
(Post 135282)
In all honesty, driving the TCH at 50-55 mph based on my experience tends to yield about 47-50mpg. At 65-70mph it tends to yield me about 42-45mpg. A considerable rise in FE (about 11 % if you take the upper limits)
Originally Posted by chiedoziedike
(Post 135282)
Your "apples to oranges" comparison sheds more light to the fact that you do not know what you are talking about.
I know you've already made up your mind that this is unsafe and wastes your time, and that's fine. Just don't assert that the mpg gains of slowing down are negligible because they are not. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Im going to run the same tests on our Grand Caravan this week if possible. I expect that it will also show a significant FE % drop at speeds above 55mph.
Sorry about the NJ speeding trucks. Actually in Ohio the limit is often 55mph for them and most go 60mph. Those that go 70 tend to get picked off by the State Troopers :) I have noticed trucks tending to drive slower this summer - all the better for wind blocks. Also - 45-55mpg in a TCH doing 70-80mph?! That is pretty astounding as I expect my HCH2 to get 40mpg TOPs at those speeds. |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by spartybrutus
(Post 135308)
Also - 45-55mpg in a TCH doing 70-80mph?! That is pretty astounding as I expect my HCH2 to get 40mpg TOPs at those speeds.
I've finally gotten to the point where I can sometimes get 55 mpg on a 25-mile commute that includes 19 miles of 72 mph interstate, in an HCH II, running light air conditioning, with a hint of tailwind. When I knock it back to 65, I get that FE consistently. If I were to knock it back to 55, I'd be getting 60 mpg, my sense is (from trying it in different segments from time to time). By the way, in all this talk of speed limits, remember the maxes are different in the West -- we're pretty much all at 75 out here. In a 75, 55 *is* 20 under the limit, and of course, actual speed of traffic is 80-85. As for trucks doing 70 . . . many companies limit their trucks to 65 -- which is why you hate to see one pulling out to pass someone in front of you -- unless you're driving a hybrid! cheers -- doug |
Re: Hypermilers - Post SAFE High FE Driving Tips
Originally Posted by spartybrutus
(Post 135308)
I have noticed trucks tending to drive slower this summer - all the better for wind blocks.
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