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Considering ditching my 2018 after owning a 2007 for 16 years

Discussion in 'Gen 4 Prius Fuel Economy' started by liznowen, Jul 27, 2023.

  1. liznowen

    liznowen Junior Member

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    I bought my beautiful, funky 2007 prius new with 31 miles on it and I loved it and it loved me through many years. My husband decided that I needed something less sketchy for a solo 3400 mile road trip with our kids in May so we retired the old girl and picked up a new to us 2018 with 110k miles. It was getting 45/46mpg but I figured it needed a little love and care and routine maintenance and it would pop up to 52/53ish because that’s what I read was pretty reasonable to expect with normal use.

    First we replaced the tires with Michelin x-tours, got it aligned, changed the oil, and replaced the 12v. Still getting 45/46 after breaking everything in on the long road trip. Replaced spark plugs, and the engine/cabin/HV air filters, and pcv valve just for good measure. Still getting 45/46.

    We’re changing the brake pads and getting a better look at the rotors this weekend but my heart isn’t in it and I feel like this Prius is cursed, maybe by my old girl because I abandoned her. I was still getting 43-46mpg with the 07, depending on how close I was to needing an oil change or if it was really hot/cold. I drive this new one the same way I did my old one, not like a maniac but also not so slow as to get myself run off the road by every lifted truck in town (there are tons). I’m pretty light on the air conditioning use. I almost never carry more than 400lbs worth of humans around and there are no bricks in my hatch.

    If anyone has some insight that could account for why this car is getting such lousy mileage, I’d love to hear it because I always thought I’d be a Prius driver for life and I have no idea what I’ll buy if I sell this car.
     
  2. ColoradoCrow

    ColoradoCrow Active Member

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    Man. I hear you. I'm reluctantly selling one of our Gen 2's but 4 cars with 2 drivers is too many. If I HAD to buy again I'd buy a 2020 Prime Limited. Currently looking at a M3. The Gen 2 is rock solid and we are keeping one of ours...for all the reasons you just mentioned. Good luck to you.
     
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  3. bisco

    bisco cookie crumbler

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    Could be as simple as different tires
     
  4. liznowen

    liznowen Junior Member

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    Different than the ones we put on it 4,000 miles ago?
     
  5. bisco

    bisco cookie crumbler

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    different from the 2007
     
  6. vvillovv

    vvillovv Senior Member

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    The cars driving history data plays a big part in what kind of mpg can be expected from a Prius.
    One thing you can check are the odometer trip meters to see if any of them show different mpg ratings.
    Typically, the slower a Prius is driven the better the mpg readings will be. But if a Prius has been driven faster for several years the car kinda settles into predictable mpg area and to change that prediction the car is making from the way it's been driven for several years takes a long time before a new driver can see mpg improvements.
    My sig other drives the Prius like a regular car. So to keep the cars mpgs in a range that I can live with I have to drive the Prius a lot slower than I normally would whenever I can.
     
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  7. liznowen

    liznowen Junior Member

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    Hmm. I was under the impression that replacing the 12v battery would reset the system so it had to relearn your driving habits.
     
  8. bisco

    bisco cookie crumbler

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    mpg's measured at the pump shouldn't reflect anything except driving parameters for that tank
     
  9. vvillovv

    vvillovv Senior Member

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    There hasn't been to much public discussion about Prius History Data, where it's kept, what data is stored, and for how long data is kept. Some discussion, but not anything the average owner normally remembers. unless they have the diagnostic software the dealers use, techstream. It's true that some setting and data is lost when the 12volt battery is disconnected, but there is other data that is stored for the life of the car and can't even be cleared with techstream. And history data is one of those mysterious things about the car that is probably only well known by toyota engineers that programmed how the systems work in unison.

     
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  10. bisco

    bisco cookie crumbler

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    that data would be in the proprietary black box.
     
  11. Doug McC

    Doug McC Active Member

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    A little late to the discussion but how many miles on the ‘18? A couple of things I’ve noticed with my ‘22 is it has a lot of little bells and whistles that can be turned off that affect the mileage by reducing the 12 volt accessory load (not a huge amount but some), and when we drive 70 as compared to 55 there’s a 20 to 25 % drop in mpgs!
    Additionally, even though my wife and I have similar driving habits we experience approximately a 10% difference between us. Don’t know if any of this helps.
     
  12. ColoradoBoo

    ColoradoBoo Senior Member

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    My wife has a 2017 LE and I have a 2021 AWD and mine gets significantly better MPG....usually over 10 mpg more. (If I pay attention to my driving, I can actually get over 70 mpg on my 40-mile commute to work which is over mostly rural paved roads.)
    Her 2017 has had the engine oil changed every 3,000-5,000 miles (sometimes less than 2,000, I change it every 6-months or 5,000 miles), I drained and filled her radiator coolant and transfer case coolant at 5-years as well as the transmission. I've cleaned out her MAF Sensor and throttle body and checked her brake pads to ensure they aren't rubbing, which decreases MPG.
    It's a mystery why her car doesn't get much higher than 50 mpg but, still, that's higher than any other hybrid car I'm aware of. (A co-worker has a Ford Fusion and he told me he barely hits 35 mpg.)
    Maybe tires does have more of an impact than I'm aware...I did replace her OEM Toyo tires with General Altimax a few years ago. (And they seem to be holding their tread much better than those OEMs which were almost bald after just 24,000 miles.)
    There's a video on YouTube by The Car Care Nut and he teaches how to use the "pulse and glide" method of driving with hybrids which is what I do to get my 70+ mpg when I'm wanting good mileage. (But I usually drive like a bat out of heck so she's only getting around 60 then.)
     
  13. Gokhan

    Gokhan Senior Member

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    If I can keep my speed below 60 mph, I get close to 70 mpg in my 2021 Prius Prime Limited. I can even get 75 mpg or higher. I get 120 mpg in freeway stop-and-go driving in the summer.

    How fast are you driving? Don't expect to get above 50 mpg if you drive 75 mph. Gen 2 wouldn't even get over 40 mpg at 75 mph.

    Other than that, if the engine is not properly broken in, its lifetime fuel-economy would be reduced.

    Moreover, the spark plugs need to be replaced at 100,000 miles. That could be the main reason for your inferior mpg. You may need a fuel-injector cleaning as well.