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Engine block warmer

Discussion in 'Gen 3 Prius Fuel Economy' started by mengoni, Mar 16, 2019.

  1. mengoni

    mengoni Junior Member

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    I know that the Prius operates best at around 70°f. This winter was a bit tough on my mpg, only around 43 mpg, ugh. But it warmed up this week and my mpg was 52.83.
    How much mpg improvement could expect to see if I installed an engine block warmer.
    FYI... I use my Prius to deliver pizza at night driving around 350 miles each week

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  2. Salamander_King

    Salamander_King Senior Member

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    Do you have the ability to keep the block heater plugged in between deliveries? If you are plugging in the block heater only over night, I don't think it would do much to improve the mpg. No direct experience, but the engine heater would be good for prolonging ICE lifespan by relieving stress in the cold morning startup and may improve mpg if your driving habits mainly consist of a very short trip while the engine is cold.
     
  3. Grit

    Grit Senior Member

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    Before you actually go all out engine block warmer, it's only good for start up process. In your shoes, I'd get a tempature real time reader first and then block entire lower grill. Only when I drive around town <45 mph, I block entire lower bottom grill all year round including summers. It squeezes out like a champ but be sure to monitor mg1, mg2, radiator, coolant and engine temp as you do this.
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    Block heater would be especially good if you had one short trip daily. It's that first cold-start that it really helps with.

    Full disclosure: we got the block heater installed, eight-o'clock-day-one, and use it more-or-less without fail before the first cold start of the day, for a roughly two hours. Don't regret it. It basically raises coolant temp about 20~30C, gives you a leg-up on the warm up process. Maybe helps with engine longevity too, since cold starts are the roughest time for an engine?
     
    BruceInOKC likes this.