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Mediocre MPG - normal or should I be concerned?

Discussion in 'Gen 3 Prius Main Forum' started by rittchard, Sep 27, 2009.

  1. rittchard

    rittchard New Member

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    I've had my first Prius now (2010 Package IV) for about a month, and have been watching the mileage on a daily basis. It's not that I'm concerned about it so much as it seems to be a fun thing for my obsessive mind to focus on while driving. I'm getting at least 3 times better mileage than my old car so nothing to feel bad about in the grand scheme of things.

    Anyway, prior to buying the car, I had seem many reports of regular MPGs in the 50s and 60s and more for the 2010 model, so I was pretty optimistic that with my almost exclusive city (and fairly conservative) driving, I'd do pretty well myself. Thus far it looks like with my normal work/life route, I'm going to settle in at around 43MPG or less, which is, to be honest, a bit disappointing.

    Now I should mention that I'm driving a LOT of stop and go (stop lights and stop signs, etc), in Normal mode, often with the air conditioner on, radio on, GPS on. And now that I'm watching it more, I notice there is a lot of gradual uphill driving, more so than I'd thought. So clearly I'm not in good conditions, or making a special effort to maximize MPG, though I do try my best to use EV mode for the last mile and hold in the ECO zone whenever I can. My typical drive, though, just doesn't lend itself to much of this, so I'm guessing this might be about the best I'm going to do without sacrificing the driving experience.

    Should I be concerned at all or does this sound fairly normal/typical?
     
  2. JRitt

    JRitt Bio-Medical Equip. Tech

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    Your mileage will improve as the engine breaks in and you learn to drive it a bit better. My first tank was 44mpg but now (3300mi later) I am getting 53mpg. To quote what some said on driving the Prius. I drive like my brakes don't work.
     
  3. Codyroo

    Codyroo Senior Member

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    Try this link

    http://priuschat.com/forums/gen-iii-2010-prius-fuel-economy/66441-you-will-not-get-50-mpg-if.html

    The original post has a lot of factors that will conspire against your quest for 50 mpg+. It seems that you have a few of them in your daily commute.

    You can improve your mileage by

    1) Making sure your tires are properly inflated. The more air pressure, the longer your rolling distance, which means you can let off the gas pedal sooner and coast longer (any cyclist will know what I'm talking about). You can fill tires up to their max PSI without worry about the tire exploding or premature wear of the center of the tire. We have many people here that exceed the max PSI by 20% or more with no tire issues.

    2) Accelerate up to speed and then coast to the next stop. The common debate here is whether or not slow acceleration is more fuel efficient than brisk acceleration. The latter (not flooring it! Just a good, brisk acceleration) will get you up to speed and then you let off and coast.

    3) Coast to stops whenever you can. This requires a bit of practice, because you need to get a feel for how long/far your car can coast and maintain speed. The trick is to get to enough speed that when you know you HAVE to stop, you let off early enough minimize brake use but aren't holding up traffic. Coasting helps with "timing" red lights. If you can hit a light as it is turning green and you are still going 10 mph, you are saving a lot of gas compared to the red light rally racer next to you who is either on the gas or on the brakes to every light.

    4) EV mode = fuel wasting. I'm sure it is cool (I don't own a Prius, so I have to assume this), but realize that the Internal Combustion Engine (ICE) charges the battery by burning gasoline. When you brake, you recapture a portion of this energy, but only a small fraction. Avoid using it, when possible.
     
  4. spinkao

    spinkao New Member

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    For heavy stop/go traffic, this is pretty normal. I am typically getting around 54-57MPG in a gen II over a tank, but in a heavy city traffic with lot of lights it drops to the mid or even low 40s, especially with the AC and radio on. You will also get better as the car breaks in and you get more experience driving it (and hone your hypermiling skills :)). So don't be concerned, your experience is normal.
     
  5. georgew

    georgew New Member

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    Yep. There are some definite exceptions but city driving is usually what brings my mileage down to about 43 - 47. Lots of stopping and accelerating at lights, stop signs...


     
  6. dc202

    dc202 Member

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    Very similar to my experience and to the topography in my region. I have lots of inclines and I drive relatively short distances most of the time.
     
  7. Felt

    Felt Senior Member

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    I own a G3, IV with 4000 miles. My "lifetime" average is 53.9 mpg.

    I am not a hypermiler ... I drive normally. But, I have learned several important things:
    To achieve my average, I must drive at least a portion of the tank at a steady 35-45 mph; I try to avoid short trips where the ICE is in the warm-up mode; and, you cannot accelerate briskly from stop light to stop light, braking hard in between (as traffic might dictate).

    I have not found the radio to impact my average; and the A/C only has a minor impact. I monitor only the Hybrid System Indicator screen, and make every effort to keep the ECO "light" illuminated. Whenever the opportunity presents itself to coast, I try to find the "sweet spot." I do not use the EV mode or the PWR mode.

    I live in northern Utah, and my daily Prius use enables me to follow these patterns. I am not sure your California environs will permit this pattern. But consider, even if you are unable to achieve the EPA figure because of the area in which you drive, no vehicle would be able to achieve it's EPA numbers either .... and you are (in all probability) still significantly more fuel efficient than in most any other car.

    For fun, take a drive away from city traffic, stop lights, and other motorist that blast you for driving relaxed (not necessarily slow - I achieve better than 50 mpg at 70 mph) - Drive 35-45 mph, glide where the road is slightly declined, and see if your mileage does not indicate 53-55 mpg. I'd bet your lower figure has more to do with your driving environment, than a problem with your vehicle.

    Good Luck
     
  8. PriusRos

    PriusRos A Fairly Senior Member - 2016 Prius Owner

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    I have the same driving conditions and am also averaging around 43 mpg so far, which was also my 3-year average for my 2006 prius (although that included a couple of long road trips where I was getting well over 50 mpg). I'm a little disappointed because I thought I'd be getting better mileage -- but I do think it's better on the highway. The lower city mileage is BTW consistent with Consumer Reports recent findings.
     
  9. ggood

    ggood Senior Member

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    Me too. Mostly short trips, lots of stop and go. Even worse in hot humid weather. Not to make you even more disappointed, but your computer is probably overstating your mpg by 5%. Just remember, you are probably still using less gas overall than all those people getting 50 to 60 mpg.
     
  10. Spartane

    Spartane Member

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    I think this statement is very important for good mileage. If you can, try to change your driving habbits so that you minimize your brake usage.

    Here's one technique to maximize your fuel economy:

    1. Accelerate relatively quickly with traffic, but allow some space to build up in front of you so that you have something to coast into when traffic slows down.
    2. When traffic begins to slow, take your foot completely off the gas pedal so that you are burning no fuel (no gasoline and no battery). The longer you're in this state the better your fuel economy will be.
    3. Adjust steps 1 and 2 above to keep your braking to an absolute minimum. The Prius will recapture a lot of energy when you brake, but the process is not as efficient as you'd like it to be.
    4. Practice repeating the above three steps to maximize your fuel economy.
     
  11. IraS

    IraS Member

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    You are definitely not alone.

    I have had my Prius V since mid July. I was rather disappointed in the fuel economy - it was no better than my 2004 Prius. I was seeing fuel economy in the high 30's.

    I had several reasons why I was getting mediocre MPG. I usually start the day with a 10-15 minute drive to the fitness center. The ICE barely warms up, and the fuel economy is low. Many of my trips are on roads with a 60 MPH speed limit, and traffic lights every 1/2 to 1 mile. I barely get up to cruising speed when I can see the next traffic light, often red, up ahead. This constant starting and stopping really hurts. The other problem was that we just ended the hottest summer on record here in Austin. Once the heat wave broke, my fuel economy jumped by 3-4 MPG since the AC isn't running at full output 100% of the time.

    Last weekend, I got to drive from Austin to Temple, a distance of around 60 miles on I-35. I made two trips each way. On the trips up and back with the car fully loaded with model train equipment I got around 48 MPG. On the trips up and back with the car empty I got around 52 MPG. The average for the tank of gas was 46 MPG (including driving around town for the rest of the week). This is way better than I normally get. I also used the DRCC most of the time on I-35, which I know is not very fuel efficient.

    The fuel economy can vary widely depending on the driving conditions, traffic, use of AC, and your driving techniques. Just be happy that your fuel economy is way better than it would be in any other car under the same conditions.
     
  12. 3PriusMike

    3PriusMike Prius owner since 2000, Tesla M3 2018

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    Along with all the other suggestions...try these two independent things:

    1) take a drive where you warm up the car, then reset one of the trip odometers and drive for 5 or 10 miles and see what mpg you can get -- you should be able to get 50 mpg or better. If not report back what you've doen for more suggestions

    2) reset one of your trip odometers often (a couple of times per day...every couple of days, etc). Do not just reset it when you fill up and watch it creep up down around 43 mpg while being concerned that you can't get it up to 50 mpg. Once you put on a lot of miles it changes slowly and it it goes up 0.1 mpg over the day or 0.2 mpg per day you are getting fairly poor feedback on your driving technique or the route you are taking. You need to get daily feedback that is comparable day to day.

    It is possible to get good mpg with some types of short city driving. I'm doing most of my driving on my 6.5 mile (one way) commute. I'm getting almost 60 mpg overall (60.3 mpg on my last tank). In a month I'll have 9 years Prius driving experience in all 3 generations, but have no special instrumentation nor do I got to any extreme measures.

    3PriusMike
     
  13. rittchard

    rittchard New Member

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    Thanks for all the great replies to this thread, definitely made me feel more comfortable all in all.

    Just thought I'd follow up a bit. I now have a total of about 800ish miles on right now and the overall average is I believe listed around 44 but in reality is probably less than that. I recently had to drive back to the dealer and that was probably the nicest drive my poor Prius has had. In that trip (about 40 miles total), the overall mileage increased from the 43 range to 45.5 - so without doing the math, clearly it was doing pretty well.

    I'm hoping for some improvements as the car "breaks in" but I'm really not expecting too much considering the type of driving that is normal for me is probably some of the worst conditions you can drive in. I rarely get a chance to accelerate at all, so the whole "pulse and glide" thing is next to impossible.

    All in all I'm pretty happy, I now get gas about every 3 weeks (instead of 2), and each fillup is half what it used to be :)
     
  14. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Each Prius has different driving conditions to cope with, so gets different mileage. As you learn what the Prius likes and hates, and adapt, it gets better mileage. Expect better milage as the car breaks in (up to 10.000 miles) and as the driver learns to 'favor' the cars features. I definitely find myself breaking earlier and gentler than before, maximizing regeneration, I have been coasting to stops more as well. (My goal is to use less gas, not get better mileage, but they are often similar)
     
  15. john burns

    john burns New Member

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    I have had my 2010 IV for about three weeks (600 miles)

    I am averaging 55 MPG.

    My prior car was a 2005 Honda Civic hybrid that I averaged 48/49 MPG

    You have to learn to drive the car. I find the techniques I used on the Civic are the same as the Prius. As stated in an earlier post, drive like you do not have brakes. Accelerate slowly, coast when you can, and then coast some more.

    I'm still experimenting with the Prius, but I plan on topping 60 MPG

    Will let you know how I do.
     
  16. PriusRos

    PriusRos A Fairly Senior Member - 2016 Prius Owner

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    I've had my 2010 for a couple of months now and a little under 2,000 miles. My average so far is only around 44 mpg (calculated). I am not a newbie driver because I had a 2006 Prius for 3 years prior to getting this car and I've read about and practice all the techniques. Although I was often able to get over 50mpg on the highway in the 2006, the lifetime agerage over three years was under 43 mpg.

    I've also been a little disappointed that I'm not showing better results but, like you, I drive in a lot of stop-and-go traffic and the terrain is very hilly. My daily commutes are short (under 5 miles each way, usually) so the car barely has a chance to warm up. The hills and the stop signs and red lights are really killers -- especially because it seems that I always have to start up from a stop on an uphill slope. While I've had highway trips where my mileage goes up to 65mpg, it's been because it's more downhill and there's no traffic; on the return trip it can drop down to below 47 mpg. It sometimes seems though that my trips are uphill in both directions and that I have a special red-light triggering mechanism built into the front of my car! :D
     
  17. adamace1

    adamace1 Senior Member

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    You should stop using ev mode to go the last mile this will hurt your mpg alot. You can't transfer gas into electricity then into a battery then into energy to move your car without a large loss. Avoid that button and your mpg will go up!!!

    Draining the battery with ev mode on my car gets me over 5-10 mpg less granted i have only tried it a few times.
     
  18. cossie1600

    cossie1600 Active Member

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    I get 43mpg, but whatever, 43 is still better than any other cars on the road.
     
  19. alex65001

    alex65001 Junior Member

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    I have to say I don't understand the suggestions to avoid EV mode. I use it as much as I can, and find that the time spent with the MPG at 100+ help to bring up the average MPG. I have 1000 miles on my car and have gotten about 55 mpg on each of two tanks of gas. I get the theory, that the ICE will have to recharge the batteries, but draining and charging happens naturally anyway during regular driving. In my experience, the batteries in EV mode require little from the ICE above what they get during driving around.
     
  20. Hippie

    Hippie New Member

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    Whoa, brother! Take your foot of the gas, puff puff pass, and take an anger management class! Life's good my man, don't sweat the small stuff and if you do, I wouldn't worry about a shower!

    Peace. Love. Obama.