Any PNW 3rd gen owners here?

Discussion in 'Gen 3 Prius Fuel Economy' started by koukilights, Jan 3, 2020.

  1. koukilights

    koukilights Junior Member

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    In both my 2nd gen and my 3rd gen my MPG seems to take a pretty noticeable hit in the winter time here in the PNW, more so than in Colorado.

    I recently picked up a 2011 and for the life of me, I cannot get over 40mpg (ecu calculated)
    It does have 217k miles but everything seems to be ok, no CEL, no oil consumption as far as I can tell, no worn out suspension or drive components

    I have 195/65R15 michelin defenders aired up to 42 psi .
    Brand new cabin and engine air filter
    Auto trans fluid change with OEM WS ATF fluid
    Fresh oil change with 0w-20 and OEM oil filter
    Just had the car aligned with everything green on the spec sheet

    I ran a can of fuel injector cleaner in the tank that I had on hand just to see if it would help

    I get that in the winter time the cold weather is rough on gas mileage, but this seems exceptionally low. The 3rd gen should get close to 50mpg with regular driving and I'm driving as gentle as I possibly can, I'm barely going the speed limit in most cases trying not to be too heavy on the accelerator. I do keep climate control on auto around 78 degrees and I understand that will hurt mileage a little bit, but there's no way it can hurt it a whole 20%

    Is it a combo of the colder weather and perhaps a winter blend of fuel that contains less BTU's?
     
  2. Raytheeagle

    Raytheeagle Senior Member

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    What are your driving patterns and how far is your commute?
     
  3. bisco

    bisco cookie crumbler

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    did you read the egr threads before purchasing?
     
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  4. Grit

    Grit Senior Member

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    That’s ridiculous, reading about a car’s common issues Prior to purchase? Who even does their due diligence before buying a car? :LOL:
     
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  5. Grit

    Grit Senior Member

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    Since history is unknown I would pull the egr pipe and see if there’s any significant build up. Hopefully you picked it up for no more than a few grand with those miles piled.
     
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  6. ryano7700

    ryano7700 Junior Member

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    I have a 2011. I drove until last year. I had a 26+ mile commute. I never set heat above 70 degrees. I could maintain about 45-46 mpg. Lowest being 42 or 43 mpg. Overall I averaged 48.2 for 7 years. Also, mine is 5 that has 17 inch wheels. Now has 130k miles.

    Now, my son has driven for a year. Has about a 4 or 5 mile commute. He hasn’t ever gotten higher than 42 or 43. Usually gets 40. He uses the heater a lot more than me.

    so I think yours is performing normally.
     
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  7. koukilights

    koukilights Junior Member

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    Commute is about 8 miles one way of highway driving. Although I have taken it on longer 50 some mile trips to see how the mpg's look

    Ok, you got me, I only briefly read them before purchasing, but with how advanced the ECU is wouldn't it throw a CEL if anything was wrong with the EGR?
    Reading more up on it now it seems people just complain of a CEL and possibly overheating with a clogged EGR. Both issues, I do not have.
     
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  8. bisco

    bisco cookie crumbler

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    iirc, some have clogged without an engine light. hopefully someone more knowledgable than me will chime in.

    i wouldn't hesitate to clean it, but the fact that it has made 217k is a good sign.
     
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  9. koukilights

    koukilights Junior Member

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    When you say clean it are you talking of the EGR valve itself? The EGR pipe to intake manifold? The EGR cooler? Or all of the above?
     
  10. Mendel Leisk

    Mendel Leisk 'Orrible Oracle

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    The simplest way to see where you're at, is to check the degree of carbon build up in the EGR pipe, a stainless steel connecting pipe between the EGR valve and intake manifold. Watch @NutzAboutBolts video #16 here:

    Nutz About Bolts Prius Maintenance Videos | PriusChat

    Two or three other videos linked there too, for the full cleaning of the intake manifold, full EGR clean, and Oil Catch Can install.

    Good thread:

    EGR & Intake Manifold Clean Results | PriusChat

    Another:

    Oil Catch Can, Eliminate that knock! | PriusChat

    Some tools worth having:

    E8 Torx socket (mandatory)
    E6 Torx socket (optional, but good to have, to remove the throttle body studs from intake manifold)
    3/8" ratchet wrench, regular and long handle, flex head, you can never have enough (or 1/2 plus reducer)
    1/4" ratchet wrench, or 3/8" to 1/4" reducer
    Ratchet extensions: you can never have enough
    Long needle nose piers, straight and bent tip
    Ratcheting 12mm box wrench (optional, but makes disconnection of the EGR cooler from exhaust easier)
    Torque wrench (3/8" and 1/4" both good to have)
    Floor jack and safety stands (or ramps): basically some method to raise front, if you need to take underpanel off, which you may need to, both for access and to recover dropped items.
     
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  11. bisco

    bisco cookie crumbler

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    what mendel said^^^^^
     
  12. Threej

    Threej Member

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    PDXer with a 2010.

    I generally get 55mpg in summer, and 50 mpg in winter (ECU). That drops to 50/45 in heavy rain, which seems to be the biggest mpg hit for me.

    The only time I *ever* get below 40 mpg is if I'm doing short trips < 5 miles, or maybe navigating very steep hills.

    Things that come to mind:
    -Trip: Are they over 10 miles? Reasonably flat ground?
    -12 Volt Battery. We here lots of stories of getting new one on fixing mpg issues for some reason.
    -EGR cleanse. At 200k it'll be pretty clogged up. Fixing this gave me a 5 - 10 % MPG improvement.
     
  13. Grit

    Grit Senior Member

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    Even merging onto the highways and getting up to speed from a full stop? You still get above 40mpg o_O
     
  14. Threej

    Threej Member

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    Yeah, the 10 miles of driving after more than cancels out the gas spent to merge onto the highway, unless maybe I'm merging uphill.
     
  15. tonynap

    tonynap Member

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    Spark plugs? If someone changed them at 90 instead of 120k, you're long overdue.
     
  16. koukilights

    koukilights Junior Member

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    20200109_153131.jpg

    Spark plugs looked pretty old. No idea how many miles/years on them but they were probably ready to be replaced. My EGR pipe was dirty but no where close to being clogged. I intend to take out the EGR cooler, valve, and pipe and give them a through cleaning when my E8 torx socket comes in.
     
    #16 koukilights, Jan 10, 2020
    Last edited: Jan 10, 2020
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  17. Mendel Leisk

    Mendel Leisk 'Orrible Oracle

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    Those may be the original plugs, pretty grungy.

    Clean intake manifold too. Pay special attention to the EGR channels. Take off the MAP sensor (just below and to right of throttle body, and spray with MAF sensor cleaner. The manifold itself maybe brake cleaner, and some sort of pipe cleaner brushes down the EGR channels. (I just used a stainless steel straw cleaner brush for this, works well.)

    Also clean the intake ports. Don't spray in the latter, just use a rag soaked with brake or carb cleaner. Be careful to not push crud onto the injector tips.

    You can remove and clean the PCV valve with carb cleaner. Or replacement might be good, with your miles. New ones come pre-coated with a thread lock. If reusing, I would recommend to clean threads thoroughly with brake clean (both male and female side). Don't spray brake cleaner into the hole, apply to a brush or cloth. Then put a bead of something like Permatex ThreadLocker 243 (medium strength, and designed to work even if there's slight oil residue).

    Again, note when removing throttle body, you can leave it's coolant lines attached.

    Attached is some repair manual info regarding intake manifold, throttle body, EGR, PCV.
     
    #17 Mendel Leisk, Jan 10, 2020
    Last edited: Jan 10, 2020
  18. AzWxGuy

    AzWxGuy Weather Guy

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    I'm not a PACNW, just a comment on what has been said. The electrical system will be constantly trying to charge an old, depleted 12V battery. You'll get a couple months of lowered MPG, followed by the inevitable dead battery one cold morning.
     
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