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101k now / Never done any maintenence, now i'm getting poor mpg. What do I do?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by 240sxer, Apr 5, 2010.

  1. 240sxer

    240sxer New Member

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    38.6mpg still.. Should I just take it to the dealer?
     
  2. jayman

    jayman Senior Member

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    I'd worry the dealership would be clueless and the only thing you'll notice is that your wallet is lighter
     
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    If you haven't had your wheel alignment checked yet, you might consider having that done next.

    Have you taken a road trip of 100 miles or more, recently? I'm wondering what mpg you can obtain under conditions where you are driving at relatively constant freeway speeds.
     
  4. 240sxer

    240sxer New Member

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    I've taken it on a few 80 mile trips. The mpg was about 42mpg, the same trip, which I've made many many times would have normally been around 50+mpg.

    I still haven't done the alignment, I'll do that this weekend. The freeway and city seem bad, I can't tell if any one is worse than the other.
     
  5. paprius4030

    paprius4030 My first Prius

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    Did you clean or install a new Mass Flow Air Sensor? I heard that could be one cause of bad mpg's if it gets dirty?
     
  6. SageBrush

    SageBrush Senior Member

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    You are running out of easy things to fix, and the lack of DTCs is curious. Increased PSD friction maybe ? I would not delay in changing that fluid.
     
  7. 240sxer

    240sxer New Member

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    I'll be doing an alignment this weekend, I'll change the Trans fluid.... That's what you are talking about right?
     
  8. jdenenberg

    jdenenberg EE Professor

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    PSD - Power Split Device, the "planetary gear set" that is the core of our Prius transmission.
    HSD - Hybrid Synergy Drive, The overall system which includes the two Motor-Generators (MGs, which are packaged together with the PSD) and the firmware in the various programmable controllers.

    Basically all of these terms are used interchangeably in these discussion groups.

    JeffD
     
  9. SageBrush

    SageBrush Senior Member

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    Yep, the trans fluid. Good Luck!
     
  10. 240sxer

    240sxer New Member

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    Ok, I got an alignment today, I drove it about 30 miles after and noticed zero difference. The alignment was not too far off (which is amazing since it had never been aligned and I've got 102k now).

    I ordered the trans fluid, and I'll be changing that this week when it arrives.

    I feel like it's my traction battery that's the issue, or something related to it. Is there any way I can test that stuff?
     
  11. XxDarkSidexX

    XxDarkSidexX New Member

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    the spark plugs, transaxle fluid, and cleaning MAF, throttle and PVC + new engine air filter = i got my 45-50 back. But same rules apply as when I drove the car new and got 45-50mpg normally, in order to get that 50mpg I can't do my normal 85mph. A trade off I'm okay with that. with tire rotation, alignment, and 50psi in tires I'm back to normal mpg. money i saved from going to dealership in O.C. I drove to SF for the weekend, was nice. car performing as usual, fantastic even at high rates of speed. You had to order the trans fluid, was your local dealership was out of ATS WS?

    other then that try seafoaming it? lol!
     
  12. 240sxer

    240sxer New Member

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    I put Seafoam in it earlier today lol.. I doubt it'll work but I don't see it damaging anything so it's probably just gonna waste my money at worse, and at best it might help. I ordered the fluid from redline.

    I did the spark plugs, MAF, throttlebody, aux battery, alignment, 45psi, air filter....

    Nothing seemed to give it any significant gain. I even tried putting a tank of premium through it, which resulted in the worse tank of the car's lifetime (34mpg), but that at least shows it's not some sort of timing retardation issue.

    A about a year and a half ago my lower air valance thing was hanging from hitting it on parking stopper things and stuff so I removed it, I knew it would effect aerodynamics but I never noticed a difference. I guess i'll replace it now... But I know that's not the problem. I'll do the trans fluid when it comes, then i'll replace the coolants, not sure what to do after that.

    It does sometimes seem like the ice turns on more often than it used to, but I might just be paying more attention, but is there any way i can test the Traction battery? How long is the warranty in Cali?
     
  13. derkraut

    derkraut Member

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    I assume you've checked the tire pressure? (optimum for best pg is 40-42psi) When did you last check/replace the engine air filter? Dirty/clogged air filter can reduce mpg significantly.

    Whoops! I see you've done that already.
     
  14. 240sxer

    240sxer New Member

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    Drove it a bit with the alignment. Didn't seem to make any difference. I received the trans fluid yesterday, I'm going to replace that today or tomorrow..
     
  15. usbseawolf2000

    usbseawolf2000 HSD PhD

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    By any chance, did you install roof rack or change new wheels / tires?
     
  16. SageBrush

    SageBrush Senior Member

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    OP, I think you are right in considering the traction battery if a transaxle change does not improve the mpg. Try PM'g Pat Wong or Bob Wilson for advice how to test.

    The CA warranty on the battery is 150k miles.
     
  17. 240sxer

    240sxer New Member

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    150k makes me feel much better. Nah no roof rack or new tires. I know those would effect aerodynamics. Nothing on the car changed...
     
  18. andyprius

    andyprius Senior Member

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    Warranty, covers failure of one or more cells, which could equivacate to LOW mpg (lower than your normal) So.............does one go to the dealer complaining of low mpg OR a bad HV battery. I'm presuming a charge for the HV check.:cheer2:
    ,'
     
  19. 240sxer

    240sxer New Member

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    Is there any way I can check it myself? I'm still getting the low mpg. I've done everything, I don't want to go to the dealer for them to just throw money at it.
     
  20. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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