Is Prius Gen 4 more reliable than Gen 3?

Discussion in 'Gen 3 Prius Main Forum' started by Mamalucy, Oct 20, 2025 at 2:41 AM.

  1. Mamalucy

    Mamalucy Junior Member

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    Original owner, Bought 2010 early Gen 3 having some problems. 122,500 miles, wondering if better to get a newer Prius Gen 4. Don't care for the newest model.
    Any thoughts? Thanks!
     
  2. PriusCamper

    PriusCamper Senior Member

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    Yes

    But problems are limited to head gasket and piston rings...

    You can put a Gen 4 engine in a Gen 3 Prius and solve everything.
     
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  3. Tombukt2

    Tombukt2 Senior Member

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    Seems like a lot of hybrids are all of a sudden coming down the pike it's going to be interesting for sho. Even Lamborghini is going all hybrid.if I can figure out battery situation for gen1 volt it's one the better cars on planet . Easy to find cheap.
     
  4. ASRDogman

    ASRDogman Senior Member

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    Why would you get a newer car? What's wrong with the one you have now?
    And you don't like the way it looks, WHY would you spend money on it?

    If your car is paid for, and you like it, WHY get rid of it?

     
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  5. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Not sure about that. Getting 4th gen EGR to work in gen 3 is not easy, and afterwards many experienced overheat issues, resorted to modding thermostat.

    If our 2010 ever gets to that juncture, say failed head gasket and runaway oil consumption (which I suspect is pure cargo cult now…), the shopping list would be (gen 3) short block, engine overhaul gasket kit (Toyota, including head gasket), and replaced head bolts.

    And continue to clean the (3rd gen) EGR system periodically.
     
  6. bisco

    bisco cookie crumbler

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    overall, gen 4 has about the same reliability, if you don't count the brake actuator, egr circuit and head gasket.
    it has some different issues, but nothing too major. beware the leaky exhaust coolant heat exchanger on early models
     
  7. BiomedO1

    BiomedO1 Senior Member

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    This all depends on the honesty and experience of the mechanic you take the car to, especially if you don't know anything about cars. As a general rule, things usually start breaking around 150K miles on any car. This is where your mechanic's honesty and experience comes in. A smart and honest mechanic can usually get the job done, so that the repair will last - not necessary the cheapest. A shady, dishonest mechanic may also fix the problem, cheap but the repair will only last the warranty period he/she gives you.

    It comes down to; pick your poison - Cheap short term solution or slightly more expensive long-term solutions.

    Statistically speaking, the gen4's seems to have a better track record than the gen3's, but that may be because they are newer with less wear and miles on them....
     
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  8. bisco

    bisco cookie crumbler

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    well, you've got about 9 years on the gen 4. iirc, gen 3 issues started cropping up well before that
     
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  9. Mamalucy

    Mamalucy Junior Member

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    Hahaha, thanks for your feedback!
     
  10. Mamalucy

    Mamalucy Junior Member

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    Thanks!
     
  11. Mamalucy

    Mamalucy Junior Member

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    Thanks! Have an honest independent mechanic. But the costs to fix are accelerating.
     
  12. Mamalucy

    Mamalucy Junior Member

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    Hahaha thanks!
     
  13. rjparker

    rjparker Tu Humilde Sirviente

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    Gen4 is far better than gen3. A redesigned engine eliminated head gasket issues independent of overheating which is common on gen3. Redesigned egr pulled exhaust gasses after a cat rather than before and increased the egr cooler size. Redesigned cylinder cooling evened out cylinder temperatures. Brake booster failures common in gen2 and 3 are rare on gen4. Inverter problems are unheard of a gen4 but so typical on gen3 a class action win extended Toyota's already long 15 year warranty to 20 years. Even with a warranty, sudden inverter stranding is no fun, ask how I know.

    Excessive oil burning in gen3s is real; the gen4 redesign solved that as well.

    Lithium hybrid batteries were available in some gen4s, never in North American gen3s. Regardless, hybrid battery expense can be expected in any hybrid, therefore newer is better.
     
  14. ASRDogman

    ASRDogman Senior Member

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    Yes, but still cost less than a new car.
    And you can learn how to do a lot of those jobs. Labor is usually the most expensive part.