Right amount of coolant??

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by priusrust, Mar 10, 2026 at 1:51 PM.

  1. priusrust

    priusrust Member

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    went to Toyota parts....asked how much anti-freeze coolant my 2016 takes.
    Parts guy looked it up and said 13 quarts ......

    Then looked up cooling system in my owners manual, and it tells me for capacity: 6.2 quarts (gasoline engine) and 1.5 quarts (power control unit).

    I'm confused.....I want to drain coolant and fill up with new coolant. Simple.
    I asked them about discrepancy and they and they honestly were mystified....not slightly off...it's double!
    Help appreciated, thanks!
     
    #1 priusrust, Mar 10, 2026 at 1:51 PM
  2. rjparker

    rjparker Tu Humilde Sirviente

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    Generally you only get half out on a drain and fill.
     
    #2 rjparker, Mar 10, 2026 at 1:52 PM
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  3. Mendel Leisk

    Mendel Leisk MMX GEN III

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    I think it's mechanically similar to gen 3, at least for coolant volumes. From my notes when I changed both circuits:

    engine coolant drain: 4.25 liters roughly
    inverter coolant drain: 1.5 liter roughly
     
    #3 Mendel Leisk, Mar 10, 2026 at 2:42 PM
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  4. a2058

    a2058 Junior Member

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    I usually keep two 1 gallon Toyota SLLC on hand when I drain and fill both, then get a little bit left over for topping up…
     
    #4 a2058, Mar 12, 2026 at 7:56 PM
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  5. priusrust

    priusrust Member

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    So my manual (not the dealer) says 6.2 qt (5.9 L) for engine, 1.5 qt (1.4 L) for power control unit (inverter I presume).
    that is .3 shy of two gallons ......I'll do this.
    The dealer insisted, even after I showed him the manual, engine takes 13 qts!!! (3 gallons + 1 qt)
    I have to remember this is the same dealer who did the recall on my gen 2 steering column linkage, and the steering wheel subsequently became detached from steering column when driving!
    Thanks all!
     
    #5 priusrust, Mar 12, 2026 at 9:08 PM
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  6. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Owner's Manual? Numbers in there would tend to be system capacity I think, not typical drain amount.
     

    Attached Files:

    #6 Mendel Leisk, Mar 12, 2026 at 10:25 PM
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  7. ColoradoBoo

    ColoradoBoo Senior Member

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    Yep you might get half out when draining. BUT if it ends up being just half why not drive it for about a week and do the same drain and fill service? (That's what I like to do in my Tundra because the only way to drain more coolant is to use the little drain plugs on the block and no way am I brave enough to mess with those things....break one and it's a very expensive lesson!)
     
    #7 ColoradoBoo, Mar 13, 2026 at 1:46 PM
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