None of the speculations add up for me!

Discussion in 'Gen 2 Prius Fuel Economy' started by Chicagodriver, Feb 5, 2014.

  1. Chicagodriver

    Chicagodriver New Member

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    Speculations, as thoughtful as they have been, do not add up. I have considered each and every one, especially the role of weather, tires, driving style, things which I can control, or at least be aware of. When I first bought my Prius, I averaged slightly better city mpg (about 50mpg) than highway (about 49). This is Chicago, flat geography, cold winters, stop lights that change on a dime from green to red!
    The first winter my mpg was exactly the same as the first summer of driving! Simply fantastic. Despite synthetic oil changes and tire rotation, etc., I am now averaging 23mpg. The decline has occurred steadily over two years. If anything, I would say that the performance is ERRATIC! Just when I am ready to take it in again with my complaint, the city mpg skyrockets!!!! Yup, 50+ mpg. Yet, my routes and habits, including gas used, have remained the same. I am now taking pictures of the dashboard energy consumption. C'mon! 14mpg??!!!!! But of course, nothing is wrong. Phooey. Tell me another story. Company lines and owners like me still wanting to believe the company lines. I really can't afford to spend more money on service recommendations that do not work.

    Basically, I am looking for suggestions about how to get the help I need from the service people! I am currently armed with In-Drive reports for the prior 12 months vs In-Drive reports for the initial year. This includes an increase in carbon emissions (which fact probably supports an increase in gasoline rather than electrocurrent consumption), pictures of my dashboard energy consumption monitor, and gasoline bills. Originally I filled up every 6 weeks! Now it is 10 days between fill ups! Same average mileage, routes, driving style. O, and I also have great tires which have a well maintained inflation pressure. Does anybody think I can make my case this time? It is just so expensive not getting help (ie., the service bills are hundreds of dollars mispent), and the cost of gasoline is negating the investment cost of the car. I find myself actually thinking that I should just trade it in for a Ford. My old Ford was averaging better than this Prius.
     
  2. fuzzy1

    fuzzy1 Senior Member

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    To give us more clues, please read this questionnaire and reply here with as many answers as you can reasonably provide:

    Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new

    Oops, that was for the 2010+ models. Here is the one for the your 2009:

    Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new

    And when you run into a dead link trying to find "Why don't I get the EPA Mileage", try this one instead: Why Don't I Get The EPA Mileage?
     
  3. bwilson4web

    bwilson4web i3 and Prime

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    At one time there was a fairly active Prius or Hybrid Club in the Chicago area. I do not if they are still active. You might also ask over at CleanMPG.com as that is their mission.

    Bob Wilson
     
  4. bisco

    bisco cookie crumbler

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    replace your 12 volt battery.;)
     
  5. Chicagodriver

    Chicagodriver New Member

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    Fuzzy, thanks for your direction. I am in the process of trying to upload the file with the Questionnaire you provided.

    - questionnaire - What fuel economy are you expecting and why?

    I bought in May 2011 as certified used from a local Toyota dealer.At the time of sale, and for about 10 months, my gasoline consumption (according to the dash computer screen) for that period was something I bragged about:City 50mpg; Hwy 49 mpg.City driving was the primary use of the car.Only took a hwy trip for 20 miles or so, perhaps once monthly!I expect to have that same energy consumption now, as then.I SUSPECT THAT YOU ALL BELIEVE WHAT I JUST SAID REGARDING THE COLD WEATHER AND CITY MILEAGE IS SIMPLY FANTASY.BELIEVE YOU ME:I DO NOT FANTASIZE!THIS WAS A SIMPLY GREAT–ANSWER –TO-ALL-DREAMSCAR back then. I need to post the questionnaire in the following segments. Was not able to upload. Please be patient.

    - questionnaire: What are the approximate outside air temps?
    The initial period as described above, included the range of Midwest temperatures typically found from late spring, through the summer, fall, winter, and again into spring. So that would mean that my Prius performed as described above in temperatures ranging from below zero to close to 100 F. I was very VERY happy. I suspect you all may think my account is inaccurate. It is not. MY Prius was a winter personality!

    - questionnaire How long are your trips?
    My trips (one-way trips) for the first 10-12 months were primarily within the City, ranging from about 6 to 10 miles. One-way is defined as the car getting to its destination and remaining there for at least 4 to 6 hours. Currently my City trips continue to be within that range. However, I now travel the Hwy considerably more. The current Hwy trips range 20 to 40 miles round trip.

    - questionnaire - How much of it is city vs. highway? Roughly what's the average speed in overall and of each segment?Is there a lot of stop and go driving?
    In the City is always stop and go. Always has been. No way to avoid it. Yet the mpg City was exceptional that first 10-12 months! WAS 50mpg!!!!! City!!! Stop and Go. CURRENTLY my avg City is 24 mpg. No such thing as an avg speed in the City. Some open areas and conditions permit 30mph max. Otherwise ….anybody’s guess related to how you hit the lights, and traffic.
    Originally, Hwy @ 49 mpg, was a little less than City performance. CURRENTLY my Hwy driving is averaging 48 mpg. Average Hwy speed is 55 to 65 mph.
    - What's the terrain like of your drives? (e.g. flat, gentle hills, steep hills, etc.)
    City is definitely flatland. On some of the highways, there are gentile undulations. Nothing steep around here.

    - questionnaire Is your oil overfilled? No.
    How old is your 12v battery?
    The battery was replaced a few months (June) ago by a Toyota dealer. What is the voltage reading of your 12v battery after sitting over night? IDK the answer to this question. However it is a new battery. Do I really need to test it myself? (Car starts up easily. )
    Have you had your alignment checked? Any pulling or abnormal tire wear?
    Alignment was done last June. No pulling. Tires look great.
    - Are you using the factory tires and wheels?
    Yes. I had one tire replaced last June. It had a puncture. At the time the Toyota dealer told me that my other tires were fine.
    - What are your tire pressures? They are always maintained at the pressures indicated on the door panel.


    -quesstionnaire - Make, model, year, engine and transmission of previous car?
    Ford Contour 1997. Avg in pure city driving was 24 mpg.- How are you trying to drive (e.g. trying to stay in electric only?) and how hard are you braking?
    I do try to stay electric as much as possible. I am always watching the energy monitor for feedback about my driving style. But it is getting pretty scary seeing the computer monitor giving me about a 1/8 to ¼ inch height of yellow column no matter what I do! In this City, there are times when a hard brake is necessary due to the short notice of red lights at intersections. But of course, this averages out over the years and is really no different now than during the first year of driving this car. (Yet, when I look at the other computer monitor which shows the battery charge, it shows a pretty good stack of blue horizontal bars. )


    Questionnaire - Are you "warming up" the ICE (internal combustion engine) by letting it idle after powering on?

    Yes. About 5 minutes. Other than that, I never leave my car idling.
    - Are you driving using D or B mode?

    I don’t know what these terms refer to.

    - HVAC settings? Are you using the heater, AC, auto mode, etc.? If using auto, what temp is it set to?
    Yes. But I do attempt to tolerate the cold and the heat of the seasons the best I can. Temp is set to 70 when in use. And, I limit the air distribution to feet and windshields.

    Fuzzy’s questionnaire, cont.- If reporting a mileage drop, did anything significant change on your car (e.g. accident, hit a curb or big pothole throwing off alignment, oil change/other maintenance/repairs, changed tires or wheels, etc.) or your commute?
    Yes, now that this comes up, I was rammed by a car that suddenly pulled out of a turning lane just as I was moving past. It rammed me from the anterior of the driver’s door to behind the left tire. That was just about at the one year anniversary of buying this car. Late May 2012. Mileage did start its decline (as I recall) that fall, and during a winter trip, I averaged about 28 mpg Hwy.
    So, I started watching how the car performed at various outside temperatures. But there was no clear pattern related to temperature variations.
    Frankly, there were and still are, many times that energy consumption is truly significantly better in colder weather. Sometimes. The accurate adjective would be that it is an ERRATIC pattern. A couple of times this winter I was stunned when there is a freezing cold winter day when the energy consumption monitor tells me that the avg for that day’s City drive was 48 mpg!!! And the particular drive was no longer or shorter than others. My driving habits are pretty standard from day to day

    Extra information which might be of value to you in trying to help me:

    Last June I took the car in to the dealer to have a tire fixed, and to have them figure out why my mileage was so poor. They did little things, like check fuses or switches,abut also a new battery, new tire, alignment, oil change, etc. I have always used synthetic oil. The first month, the mpg were definitely improved. But my In-Drive performance reports support my own observations, the decline has been steady, and is worse than ever, currently, 23 mpg. It is not a matter of switches/ fuses. When I manually verify the computer math against actual gallons consumed, it is the same. And, I do register “fear.” Because there are times when that extremely short yellow bar (1/8 – ¼ in.) makes me think I might be stuck in a car that will not run.

    PLEASE believe what I have described about my car’s performance during its first year of my ownership. Why else would I be so frustrated and upset. My complaint and sense of frustration is empirically based, with a definite reference point for my expectations.

    Thanks. I really do appreciate your trying to help.

    Right now I am wondering about that collision which occurred at the end of the first year. How would I pursue this line of investigation?

    And finally, thank you for your kind patience in reading through my answers to the questionnaire!
     
  6. ksstathead

    ksstathead Active Member

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    No, not while accelerating. While already at speed. Reset Trip B and see what you get over 5 or 10 miles at xx mph.

    This can be compared to norms.
     
  7. ksstathead

    ksstathead Active Member

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    If your car was giving the same mpg year round, it was already erratic, as that defies logic, physics, and our collective experience. But it would vary far less by season that the hit you are taking now.

    When steady speed on an open road, what instantaneous mpg do you get, and at what speed?

    Basically, you should be able to isolate one or more areas not performing as they did, such that fuel use is doubled.
    Does the car still glide freely? Does it still shut off the ICE when it should? Etc.
     
  8. Chicagodriver

    Chicagodriver New Member

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    Well, I know my original experience does not meet with the community expectations. ( Not sure it is all physics, though. I tend to "enhance" my way with a car according to what I think it may need under varying circumstances such as weather. A little "spooky action" as they refer to in quantum realm. lol but that seems to no longer be working ) That is why I have kept repeating (defensively) that I do not fantasize this. :) I am giving you a full deck. I do value other people's time and energy.

    If by instantaneous mpg at steady state on open road, you mean, if I depress the pedal to accelerate while driving steady at say 60 mph .... it does dip pretty badly. The yellow bar can have me all the way down by 28 - 35 mpg the last I looked. I will need to update that information for you. And there is a much deeper sound to the engine. Yes, fuel consumption is from a fill at 550 miles originally, to a fill at 210 miles currently. I fill when there is only one dot left on the fuel tank gauge. That is of course pretty subjective, but it is subjectively consistent. The car glides well. I will make a point of monitoring other clues as you suggest over the next few days and report back on the findings. I get the idea.. look for clues. Good suggestion.

    Something has come to mind. You ask, does the ICE shut off when it should. The past few weeks, I have had a growing concern that I had been forgetting to shut the car fully down for the night. It "seemed" that the car was already "on" upon official startup (push of the button). Or, I would swear, I shut it down, but the doors would not lock until I reentered the car and shut it down a second time. This kind of thing. In fact, I have for the past couple of days, been trying to remember to consciously be aware of my shutting the engine off. However, habit here is difficult to make conscious. I will need to continue with this over the next few days, and see if there is something going on here. However, no odor of gasoline or fumes in the garage.
     
  9. The Electric Me

    The Electric Me Go Speed Go!

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    It's frustrating but sometimes automotive diagnosis can be like medical diagnosis. It just takes time, and sometimes things have to get worse before what is causing the problem becomes evident.

    That might be the case for you. It becomes even more frustrating when you do spend money on service recommendations without getting noticeable result.

    I wouldn't necessarily blame the service department or anyone. It's not so much a company line, as just what you do. When someone comes in with a headache, you don't tell them it could be a brain tumor. You assume the best, and try the easiest remedies first...you escalate diagnosis and concern if the problem persists.

    Unfortunately your problem seems to be persisting.

    You have absolutely nothing to lose by trying every suggested self generated avenue for improvement. Most of the suggestions are relatively cheap or simply behavioral changes in driving and operating and maintaining the vehicle. If the problem is solved...great, if not? Well you are slowly ruling out what it is NOT.....
     
  10. tanglefoot

    tanglefoot Whee!

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    There have been instances of service departments adjusting the parking brake too tight, so that it drags constantly and reduces MPG. If you have some time (and a relatively warm day), lift each back wheel off the ground and with the parking brake off, see how much effort it takes to rotate them.

    I assume the engine air filter is clean.

    Just for grins, you might try inflating the tires further, say to 44psi front, 42 psi rear. This isn't the only MPG contributor, but it's something to try.

    I assume the rear suspension geometry was checked after the accident. I wonder if one of the rear wheels could be off-caster from the impact.

    Try to relax while you're driving (maybe easier said than done, in Chi-town). Leave plenty of following distance, if you do not already.

    I like the Prius club/community suggestion...see if you can arrange to get a hypermiler to drive your car and see what the results are.

    Using electric mode as much as possible isn't always best. It's sometimes better to get the gasoline engine involved for any acceleration or climbing and only use glide for times of low-energy demand (the car does this pretty well on its own, but there's room for improvement via technique).

    How is your pulse & glide technique? I like this guide (disregard if you're familiar with all this).
    Mike with a Prius: Prius-ing for Dummies - beginner Prius mileage tips

    You might try not using "auto" mode on the climate control. It can be pretty energy-demanding.

    The large difference between your original and current readings is strange, though. Something must have changed.

    What tires are on the car, out of curiosity?
     
  11. fuzzy1

    fuzzy1 Senior Member

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    Other readers have made similar claims, but none in places with real seasons have provided fuel logs or graphs to show it. My mpg does vary by season, as shown by the graph below, and many others have shown similar results:
    [​IMG]

    This suggests that the basic car is OK once the engine has warmed.
    Are you doing the checking, or is the shop? Is pressure being measured cold in the morning, or warm shortly after a trip? Was air added for this extra cold winter?


    We like to see you post actual pressure numbers as part of the verification that you are actually checking the tires yourself, not trusting what the mechanics claim.
    Please don't do this, it is counterproductive. Electric mode is not free, it carries some energy conversion penalties that must be traded off against other losses. Let the car decide when to choose gasoline or just electric, it is already quite smart about it. While it is certainly possible for the driver to do better, many beginners actually do considerably worse and drag down overall trip mpg.
    Warmup is not necessary unless you need it to clear the windows, or will be hitting freeway speeds in the first minute or two. Even traditional cars are best warmed up by almost immediately driving away at slow street speeds. Warmup time cuts overall mpg, especially in cold weather when the cabin heat is turned on.

    When coupled with short your short city trips, this can put a huge dent in overall mpg. Your much better highway results suggest this is happening.
    What forward gear are you using, D (Drive) or B (Brake)?

    B is useful only downhill in the mountains. Flatlanders should stick exclusively to D.
    Is fan set to Auto, or low / medium / high?

    Cabin heat costs a bit of fuel even in traditional cars. In a Prius, the fuel cost is much more visible, and is larger because the engine inherently has less waste heat to be given away for free. Heating also greatly restricts the fuel-saving engine-off behavior in stop-and-go city traffic. So for best mpg, don't use any more heat than your body really needs.
     
  12. fuzzy1

    fuzzy1 Senior Member

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    While the battery should not be bad this early, it sometimes happens. Prius is also susceptible to letting it run low with repeated short trips. Considering the effort and money you have already put into trying to solve this issue, you should check this battery too.

    A low 12V battery produces very different symptoms than we are accustomed to from the past, not the familiar hard cranking and starting of traditional cars. Low MPG is a common problem.

    While a separate voltmeter is the best tool, your 2009 has built-in help to measure this battery. See these posts:
    Weird stuff happening? MPGs dropping? Test The Battery
    Entering Maintenance Mode (aka 12V Battery Check) without Switching Headlights ON/OFF
     
  13. PriusGuy32

    PriusGuy32 Prius Driver Extraordinaire

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    In this order:
    Check/replace 12v battery
    Check/inflate tires to 42psi front, 40psi rear
    Check oil level/air filter
    Block grille in temperatures below 45f (search site for directions)
     
  14. Former Member 68813

    Former Member 68813 Senior Member

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    Yap, that would explain the MPG problem. Maybe the accident damages the ECU or wiring?
     
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