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74mpg really is anyone really getting this? wats your best?

Discussion in 'Gen 3 Prius Fuel Economy' started by graham hendren, Jan 9, 2013.

  1. F8L

    F8L Protecting Habitat & AG Lands

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    What is normal life to you may be different for someone else. ;)

    Try to look at in terms of percentages. A 10% difference at 70mpg looks a lot larger than at 20mpg yet it's still 10%.
     
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  2. walter Lee

    walter Lee Hypermiling Padawan

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    Nobody believes that any vehicle will achieve its european cycle MPG rating - not even the Europeans. :p Our American EPA cycle MPG rating is widely regarded as much more realistic.:coffee: What I find really strange :confused: is that even American car manufacturers like Ford and GM refuse to sell their more affordable and value oriented high MPG European models in the USA :( ... It seems to me in these recent times that only Toyota, Hyundai and Honda have tried to provide value oriented affordable FE cars in the USA o_O , while other motor vehicle makers in the USA have either only halfheartedly served this market segment or have abandon the lower end FE segment altogether. (n):mad: :cry:

    If you drive a Prius hard(>70 mph persistently) or on many short trips, then a Prius will deliver between 38 to 45 mpg per tank(USA EPA cycle).

    If you drive a Prius normally(<=65mph) with a mix of short and long trips, the a Prius will deliver between 46 to 50 mpg(USA EPA cycle).

    If you do exactly as Toyota ascribes, a Prius will achieve between 51 to 55 mpg (USA EPA cycle) in normal driving conditions and many people are happy with this.:rolleyes:

    If you hypermile a Toyota Prius, then you can potentially get even higher fuel efficiency. In my humble opinion, this is where the true fun of owning a Prius is :p -- which is why I've stuck with hypermiling longer than I originally planned. :D These driving techniques are so powerful that even in the winter time, I am able to get my 2010 Prius fuel efficiency higher than its 50mpg EPA rating! During the summer time, I have been able to get the Prius up to 70 mpg(70 mpg EPA cycle = 84 mpg european cycle)! In addition, the 3rd generation CVT transmission Prius is much easier to hypermile than a first generation manual transmission Honda Insight (FASing and NICE on a 1st gen Manual tranny Honda Insight takes real skill).

    I think the strangest Hypermiling Technique is Driving With Load (DWL) which s a highway variation of what is known in aerospace engineering as Gravity Assist, or a Gravitational slingshot, or a Gravity assist maneuver, or a Swing-by [1] :coffee: When a motor vehicle going downhill is equivalent to a spacecraft entering the gravitational field of a star, planet, or very heavy massive object. When a motor vehicle going uphill is equivalent to a spacecraft leaving the gravitational field of a star, planet, or very heavy massive object. The uphill angle of the uphill that a motor vehicle leaves at can be thought of a the change of trajectory of spacecraft as it bounces away from gravitational field. An expert hypermiler is able to get the vehicle going fast enough on the downhill such that it can breaks free of the gravitational field while going uphill with only momentum or with very little power.


    [1] Gravity assist - Wikipedia, the free encyclopedia
     
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  3. Mendel Leisk

    Mendel Leisk Senior Member

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    I found on an extended run into the interior, about 700 km's in a day, the in-dash km/100km settled down to around 4.1 liters/100 km. This is keeping the speed between 80 and 90 kmh. Then we hit a bit of upgrade and it climbed, to maybe 4.4~4.5.

    I'd say with more care, slightly lower speed, close to level road, 4.0 liters per 100 km would be easily doable. Now, that's in-dash display. Which likely translates to around 4.3 calculated. And converted to miles per US gallon: 54 mpg.
     
  4. GrumpyCabbie

    GrumpyCabbie Senior Member

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    You can't please some people. I'm sure that Skoda diesel people are so fond of won't get 70 mpg going up hills either, nor will the BMW M3 get 24 mpg going up the same hill.

    It's commonly accepted that real world mpg figures are about 3/4 of the Euro cycle combined figures. In my daily commute I am getting an average of between 55 & 65 mpg, depending on the time of year. In winter, 55 was the average due to the engine running in the city traffic to keep my warm. In summer when the engine isn't needed, I have the window down in the city and get an average of about 65 mpg UK. This would be much higher if I didn't have to include the 20 minutes of slow, start stop driving at each end of my commute. The bit in the middle often gets upto 75 mpg+.

    Everyones commute and driving style is different, but I've driven pretty much every car out there (ok never driven a Ferrari, a Noble or a McClaren but virtually everything else including Lambo's, fancy Mercs etc), and haven't found a car to come near the Prius for mpg's. Well, some manual diesel Corsas come close but dropped right down in city traffic. The BMW 3 series diesel comes close for the similar size and a VW Bora diesel was good and fun to drive, but the Prius beats them all for mpg's.

    A lot of cars have this start stop feature now but that's only good at traffic lights and not in slow moving city traffic where I seem to spend a lot of my time. So again, the Toyota hybrid system beats diesels in that environment.

    And then there's the pollution aspect; 20 Prii make the same pollution as 1 Mondeo diesel Euro V - assuming the Prius has the engine acutally running ;)
     
  5. graham hendren

    graham hendren Geeman .. taximan

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    lol well thats good sttill have no idea wat your sayying but thanks
     
  6. graham hendren

    graham hendren Geeman .. taximan

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    all im sayying is toyota is selling this car saying 72mpg . urban and x urban the fact is this just can not be done unless you only ever drive on flat roads .
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    Just notice you're in GB. 54 mpg US would convert to 65~66 mpg Imperial. Does that make more sense? If not, I'm stumped ;)
     
  8. GrumpyCabbie

    GrumpyCabbie Senior Member

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    Correct. That's pretty much how the Euro test cycle is achieved. I also understand they go easy on the heating and a/c. But it's the same rules for every car tested to compare.
     
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  9. southernguy

    southernguy Junior Member

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    Exactly...blame the test not the participants
     
  10. Flaninacupboard

    Flaninacupboard Senior Member

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    Toyota are required to advertise the number derived from the NEDC. This wikipedia article is pretty interesting and details the test cycle:

    New European Driving Cycle - Wikipedia, the free encyclopedia

    If you read the description and think about those slow accelerations and very gentle braking, you can see a hybrid would (does) excel on this test. In fact the speed of the urban cycle doesn't require the Prius engine to even start... (the length of the test does mean the battery SOC will go low and the engine will come on to drive as a series hybrid, so fuel is used)

    I would say the test cycle is not reflective of common driving styles at all. Of note is the acceleration on the extra urban, 0-62mph is done in 76 seconds. From memory the car go 0-62mph in about 12 seconds.
     
  11. F8L

    F8L Protecting Habitat & AG Lands

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    Similarly, the EPA changed their testing procedures in 2008. The GenII Prius was originally listed at 60mpg city. After the changes city mpg dropped to something like 48mpg.
     
  12. walter Lee

    walter Lee Hypermiling Padawan

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    The truth is that before the EPA changed their testing procedures in 2008 most vehicle whether they were hybrids or a conventional vehicle were not likely to achieve their MPG rating. For example, when I bought my brand new 1990 Honda Accord LX 4dr Automatic was never able to achieve its advertised EPA +25 mpg rating no matter how hard I tried to hypermile - at which point I gave up. From what I remember then the pre-2008 EPA MPG ratings were only achievable on a manual transmission version and that while those numbers were posted on the automatic versions they were never possible and the automatic versions always achieved significantly poor results. However, the revised 2008 EPA MPG rating for that automatic version was changed to 23 mpg which was achievable when I accelerated more gently and the tire are slightly overinflated.

    Both the 2nd and 3rd gen Prius (non plug in) can achieve 60 mpg in the city but the driver must be have an elevation advantage (gravity assisted driving) or be skilled in hypermiling techniques; the new EPA standard of 48 mpg is much more realistic for the casual driver - and if you look at fuelly statistics 48 mpg seems to be about the norm for the Prius.

    Recently , because of complaints that the EPA's ratings for hybrid fuel efficiency rating are too optimistic , the EPA is once again reviewing their testing procedures for hybrids[1]. For several years, most have tolerated the difference between the EPA's rating of 48 mpg and the independent tests by Consumer Reports of 44 mpg for the Toyota Prius because the difference was small enough. However, the difference between the EPA's rating of 47 mpg combine and the independent test by Consumer Reports of 37 mpg for the Ford C-Max is 10 mpg apart - this difference that has lead to calls for an investigation on how hybrid MPG estimation and testing procedures are being done. [2]


    [1] USA Today: EPA investigating gas mileage in advanced hybrid vehicles | PriusChat
    [2] EPA to test C-Max hybrid on mpg claims | The Detroit News | detroitnews.com
     
  13. southernguy

    southernguy Junior Member

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    Consumer Reports is not accurate for fuel mpg's. They rated my Lotus Elise around 24 if I recall and my Honda Civic in the upper 20's. I was getting mid/high teens in the Lotus (Even when driving normally) and in the mid/upper 30's on the Civic both driving the same routes.

    I have tried to drive hard and get low numbers like they do in the Prius and have never been able to maintain those low numbers over a tank full of gas.
     
  14. Codyroo

    Codyroo Senior Member

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    Given Consumer Reports numbers, I can't imagine that their road test is longer than 15 minutes in duration. Likely it is around 10 minutes long. Otherwise, they would do better than 42-44 mpg for a Prius. 25 - 30 mpg for the first 5 minutes and the remaining time gets the car in the low to mid 40's.
     
  15. Lutchenko

    Lutchenko Will Perrin

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    Pretty pleased with this on my trip today

    [​IMG]
     
  16. walter Lee

    walter Lee Hypermiling Padawan

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    A Lotus Elise with its low aerodynamic drag and small frontal area gets its best fuel efficiency (about 35 MPG) on the superhighway at 55 mpg at the higher gear settings (albeit restraining yourself from going faster might be problematic ;) ) where it does not have to stop . Reportedly [1] , if one increases to 80 MPH the Elise's fuel efficiency drops to 25 MPG(4th gear ). For normal day to day driving, the Lotus Elise fuel efficiency logs on Fuelly.com indicates that the average driver is getting about an overall 25 mpg to 28 mpg.

    A Honda civic engine can be turned off and on manually by the driver while the manual transmission is in neutral ( this is the manual-basic precursor to stop-start idle technology which is in the Prius) , so it is possible to get +50 mpg on a honda civic if the driver can hypermile it.


    [1] Lotus Elise Consumer Reports 33 MPG???? - LotusTalk - The Lotus Cars Community
     
  17. graham hendren

    graham hendren Geeman .. taximan

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    was it mostly moter way under 60mph?
     
  18. Lutchenko

    Lutchenko Will Perrin

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    Mostly motorway yes but around 65mph.
     
  19. GrumpyCabbie

    GrumpyCabbie Senior Member

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    :eek: No way could i do 65 on a motorway lol. I struggle with that on an A road :whistle: and still get 60 mpg.
     
  20. Lutchenko

    Lutchenko Will Perrin

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    Yeah I know what you mean and you'd think it would be a struggle but if you consider it's the M1 an M25 at 9am then 65mph is pretty impressive eh lol