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2010 Maintenance and MPG

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by LuvLispy, Apr 2, 2024.

  1. LuvLispy

    LuvLispy New Member

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    Jonesboro, AR
    Vehicle:
    2010 Prius
    Model:
    II
    I have switched from 3800 GM cars to a 2010 Gen 3 Prius. Since 2010 is the first year for Gen3, many people say it's the "worst" years for them... Anyway, I don't know too much about the newer hybrid cars, and I am trying to see what can I do about the car.
    Car currently gets 45-47 MPG combined, has 180k miles. Previous owner did routine oil changes and coolant changes, not sure about the spark plugs and EGR cleaning though. I am planning to schedule a plug change, EGR and PCV service at my local shop.
    Since I hear many people say they get 50+ MPG, I wanna know if 45-47 is too low for the car? I live in a small city in Arkansas, I have with some highway driving, but no heavy traffic here.
    Things I have checked:
    Engine air filter looks rather new, changed by the dealer I guess.
    The 195/15 tires are rather new, tire pressure is okay. Although the previous owner or the dealer put the cheap "Starfire" and "Hercules" tires made by Cooper... Not sure if these tires bring a worse MPG? They are quite noisy, but as long they are not shaking or out of balance I am planning to put some miles on them first. Any suggestion on tire brands for the 15 inch wheels?
    For the spark plugs, should I use Iridium Denso plugs on the engine?
     
  2. Tombukt2

    Tombukt2 Senior Member

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    When we could drive the generation threes that we had here that was about the normal gas mileage everybody says they get 50 and 55 mi to the gallon yeah for about 30 minutes If that was the case you would be making 550 mi on the tank of gas and still have a gallon or so left in the tank never seen it personally
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Vehicle:
    2010 Prius
    Model:
    Touring
    Any gen 3 with 180K miles, for sale, chances are about even it's got a blown head gasket, maybe masked by stop-leak product. Don't sink any money into tires or whatever, till it's true nature shakes out.

    A check of the pipe between EGR valve and intake manifold is pretty easy to do, will give some idea of the EGR condition. See video #16 here:

    Nutz About Bolts Prius Maintenance Videos | PriusChat

    Check the links in my signature (on a phone turn it landscape to see signatures), for EGR cleaning, and dealing with head gasket. Last link is full engine section from Repair Manual.

    Head gasket failure usually "presents" sometime after 150k miles, typlically at the wall between cylinders one and two, allowing coolant to leak into one or the other of those. Symptoms include:

    1. Banging/shaking at cold starts, due to coolant in cylinder
    2. Unusually clean top of piston, in compromised cylinder
    3. Coolant level drop in the reservoir
    4. Misfire code P030X, with X corresponding to cylinder number

    To get the spark plugs out for a look the wipers and cowl need to come off. See video #13 in the aforementioned link.
     
    #3 Mendel Leisk, Apr 2, 2024
    Last edited: Apr 2, 2024
    LuvLispy and bisco like this.
  4. bisco

    bisco cookie crumbler

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    45-47 is probably average on fuelly. the only thing you can do to increase mpg's is driving behavior and low rolling resistance tyres
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    Post how that goes, especially if they do EGR cleaning. That should include intake manifold cleaning, since there’s EGR passages running through it. There’s not a lot of places that’ll do this; not sure why; it’s not that hard.

    FWIW: thanks to the shortcomings of 3rd Gen EGR, optimum would be every 50k. Neglecting it, head gaskets fail.
     
  6. LuvLispy

    LuvLispy New Member

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    Location:
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    Vehicle:
    2010 Prius
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    II
    I have checked the coolant when I bought it. Previous owner did a coolant flush last year, so it's using pink coolant. I don't see milkshake at the oil dipstick either. Not sure about the head gasket, but things look rather normal now?
     
    Mendel Leisk likes this.
  7. Paladain55

    Paladain55 Active Member

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    1. Use the tires until they are done. ROI on greenie tires isn't super high.
    2. Clean and lube caliper sliding pins at all 4 corners. They corrode and lock up.
    3. I would say do the EGR cleaning and use some ngk spark plugs or denso. Just buy from a real source so you don't get counterfeit ones that burn up 4x faster.
    4. Change the oil every 5k, check the oil every time you get gas in case its an oil burner. Probably a good idea to track oil in and oil out for every oil change.
    5. To be safe i would unplug the egr valve electrical connector until you get the egr system cleaned. You're in the head gasket danger zone.
    You can leave it unplugged forever if you want. Just get a permanent p0403 cel. arkansas has no inspections so its a good way to go.