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Are people really getting 40+ MPG in Gen 2?

Discussion in 'Gen 2 Prius Fuel Economy' started by timmyjane, Apr 12, 2017.

  1. timmyjane

    timmyjane Junior Member

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    How do you know how many gallons used if you cant trust the tank?
     
  2. jerrymildred

    jerrymildred Senior Member

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    That's why @Munpot42 said "repeat at least 4 times." You have to average them out. Every tank will be a little different.
     
  3. timmyjane

    timmyjane Junior Member

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    I stated on some of the maintenance today. I changed to spark plugs and found the two on the passenger side had rust on them, numbers 1 and 2. I seem to remember seeing something about that on the forums.

    Maybe iridium ages differently but there appeared to be quite a bit of depositing on the ends. They were supposed to have been changed about a year ago but I get the feeling that they weren't.

    Also changed out the PCV. That was a realy quick process. Super simple.

    Throttle body and mass air flow are clean now too.

    During all this I accidently removed fuel injector #1 and tore the upper O ring when I put it back into the rail. That was a mess. Ended up having to go back to the parts store but luckily they had an o ring kit.

    Picked up my fluids for transaxle change and coolant flush. I thought they'd be cheaper form the dealer than Amazon but they weren't. Should have just ordered them and saved myself a trip. Dealer didn't have any rubber grease for the calipers and they suggested to just use caliper grease from an auto parts store.

    Tomorrow I'll get to see if it runs any better.
     
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  4. timmyjane

    timmyjane Junior Member

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    I got you. Ive monitored for the last 25 fillups and have an average of 36.17 mpg. This year has been the worst. Jan=36.2 Feb=37.2 March=34.2 April=32.4. That's 11 tanks.
     
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  5. bisco

    bisco cookie crumbler

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    that's awful.
     
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  6. timmyjane

    timmyjane Junior Member

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    Mileage? Yes it is. That's why I started looking into seeing what was happening.
     
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  7. bisco

    bisco cookie crumbler

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    i hope you find the culprit.
     
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  8. timmyjane

    timmyjane Junior Member

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    Thanks. I'm leaning towards old spark plugs (that were supposed to be changed) and brakes. I doubt that a transaxle fluid change will help but I hope to do that and the brakes this weekend. Got a rattling heat shield that Id like to take care of too.
     
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  9. jerrymildred

    jerrymildred Senior Member

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    Brakes and plugs are real possibilities. Along with the other stuff you did, it'll be interesting to see your results after 3-4 tanks. Hope you get it, because those are really bad mileage numbers (even if drivers of regular cars would be thrilled with them).
     
  10. timmyjane

    timmyjane Junior Member

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    Today seemed promising. 40+ average today. There does seem to be some type of surging or oscillating at idle. I can't feel it but I could hear it when I had the hood popped. I kept thinking I could smell gas but I think it was in my mind.

    I checked out a 2016 Pruis and a Prius V today. 2016 is really nice and V is huge. Both make my little Gen 2 look bad. Ha. Cant wait till I wear this one out.
     
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  11. timmyjane

    timmyjane Junior Member

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    Seems like the sparks plugs have helped some. Being very diligent about my driving style this week but have still only managed 39mpg. Going to check rear brakes tomorrow and change fluids in the trans and try for the coolant too. I don't think the disc brakes are dragging because there is no pull to one side at all.
    Since the fluids are likely not to make a difference lets hope I find something in the brakes. If I don't what should be my next step?
     
  12. biglew8

    biglew8 Active Member

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    Someone has said before that their mpg improved a little after they did a transaxle fluid drain & refill. Did you replace both engine and cabin filters? I would also double check the tire air pressures.
     
  13. timmyjane

    timmyjane Junior Member

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    Today I replaced the transaxle and both coolant loops. Confirmed that brakes are not dragging. Tire pressure confirmed to be 42/40. Engine and Cabin air filters replaced.
     
  14. biglew8

    biglew8 Active Member

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    I would fill up gas and press reset the MFD gas mileage and then see how the next 4 tanks are.
     
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  15. coyotesafteru

    coyotesafteru Junior Member

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    I just bought my first Prius, a 2007 with 144K miles. It was getting 37 MPG on the display when I got it, and stayed there for the first week that I had it.
    After a Hybrid battery failure I got the battery replaced by Toyota. It immediately climbed to 43 MPG and has stayed there for two weeks straight !
     
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  16. eblade

    eblade Junior Member

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    My '07 has been getting right around 40-ish on the mfd, since we got it used 4 years ago. Even through the battery death last week, it was still registering about that. Got a new battery in it, and it hasn't gone above average 37 yet, but i'm hoping it will straighten out shortly. I need to find new tires first, though. replace the HV battery, and bam, two tires go flat, wtaf
     
  17. timmyjane

    timmyjane Junior Member

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    That's strange about the batteries. I wonder if the new battery has to be broken in. I checked my SOC with Techstream last weekend and after a force charge Im at 80.3%. Did I check state of charge correctly?
     
  18. bisco

    bisco cookie crumbler

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    yes, toyota does not allow you to fully charge, or discharge the battery. better for longevity.
     
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  19. biglew8

    biglew8 Active Member

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    What do you use to charge the battery?
     
  20. timmyjane

    timmyjane Junior Member

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    Held the brake and floored the gas until it wouldn't charge anymore.