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New 2014 Prius C not getting the posted mpg...

Discussion in 'Prius c Fuel Economy' started by NatalieS, Oct 17, 2014.

  1. ztanos

    ztanos All-around Geek!

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    [​IMG]
    Notice the normal airflow is blocked by foam. Yes, you could use both. Not sure which is better, depends on your personal preferences. This can be bad in warm climates, however, whereas the heater won't be.
     
  2. ztanos

    ztanos All-around Geek!

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    Not sure if you would need to have it plugged in overnight or not. That's where someone else will have to jump in. Or do a quick search, I'm sure there are tons of threads about it.
     
  3. vskid3

    vskid3 Active Member

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    Block heater helps the most on short trips, might not help a ton for you. Generally takes a few hours for the heater to heat the engine to the point that it can't any more. Plugging in at night will work, but waste power compared to plugging in a few hours before driving/using a timer.

    Grill blocking involves covering part or all of the grill openings to reduce the airflow through the radiator and engine bay. This would be DIY using foam pipe insulation or plastic and zip ties. Helps a lot with warm up speed and keeping the engine warm, especially when you're using the heater to keep yourself warm, too. I would recommend having instrumentation like a Scangauge II or Ultragauge to monitor the coolant temp, though.
     
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  4. Britt Jacobsen

    Britt Jacobsen Junior Member

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    Ya I couldn't find any detailed info on it but didn't read all the threads. Wouldn't grill blocking and engine heaters be bad in the hot summer and cause the engine to over heat? I guess you could use anything to block the grill? I ordered a leather bra because I noticed the bugs are getting in the grill that I can't reach to remove easily. I wonder if the bra would be a type of grill blocking. The grill block is benefited at high speeds I assume.
     
  5. vskid3

    vskid3 Active Member

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    Its recommended to remove most or all grill blocking in the summer, especially if you don't have instrumentation. The bra likely won't cover the grill openings. Wouldn't be good for business if your product toasted cars in Phoenix.

    Here's a picture of the lower grill block I have on my Gen2. Plastic cut from the back of a dead TV and zip tied to the grill. I've had it on the last couple months without a problem. Haven't done any long drives in 80F+ weather, though.
    [​IMG]
     
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  6. Britt Jacobsen

    Britt Jacobsen Junior Member

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    By the way how can you get to the radiator from the grill on the Prius c 2014? I have a ton of bugs stuck in there and the plastic grill is blocking my access to it?
     
  7. Britt Jacobsen

    Britt Jacobsen Junior Member

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    Does it really make a difference in the mpg?
     
  8. vskid3

    vskid3 Active Member

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    To get the bugs, you could pop the hood and spray from the back of the radiator. Don't use a pressure washer, the fins can bend easily.

    I honestly can't tell if mine makes a difference, but I'm confident that it doesn't hurt. My tanks usually cover 2-3 weeks of driving that can vary quite a bit, so its hard to tell.
     
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  9. Easy Rider 2

    Easy Rider 2 Senior Member

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    Sorry but you are getting some bad advice here.

    The block heater is not a bad idea IF......you live in a really cold area and your car sleeps outside. It will NOT make a significant difference in your total gas mileage, however, unless you make a lot of short trips starting and ending at home......in cold weather.

    Grill blocking can be dangerous if not done right and gains you little or nothing below about 30 MPH and not a lot above that.
    Done wrong, it can even make the wind drag worse.
     
  10. NatalieS

    NatalieS New Member

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    Yes, thank you! I checked my tire pressure and it was alarmingly low, we're talking low 20s here, not actually sure how the tire pressure light didn't go on. Back up to 38-40 now and my mileage improved a little bit.
     
  11. NatalieS

    NatalieS New Member

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    I've gotten 700 km on a tank but also 614 lately so it varies with weather.
     
  12. NatalieS

    NatalieS New Member

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    I will try it on my next tank to see if it makes a difference. So far, I think the main drop was initially because of the tire pressure and then the colder weather. Guess I just have to keep reminding myself that anything the Prius C gets is better than my 2010 Matrix XR which had a 22 mpg rating and on most days didn't even get as much.
     
  13. ztanos

    ztanos All-around Geek!

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    Now that you have the pressures up to where you want them. You should retrain your sensors. The procedure is in the owners manual and has something to do with the white button under the dash. Sounds like they got set to a threshold well below factory.
     
  14. Mendel Leisk

    Mendel Leisk Senior Member

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    Yes you can use both. I see Toyota Canada offers the block heater for installed price of $236 (CAN). Should be similar in the states, likely cheaper. Typically around 2 hours plug-in will warm the engine block to a plateau, with coolant temp raised roughly 25C above ambient. In really cold you might need 3~4 hours to achieve the same. The objective is not a fully warmed engine, just partially warmed.

    TOYOTA CANADA: Language

    Grill blocking is another tactic, assumes the grill opening is designed for worst case, hot summer driving, extended hill climbs. It's good to research it though, don't just completely block, and find out at what ambient temperatures to block, or not. There's likely a zone of the grill that has the inverter radiator behind it, it's best to avoid blocking that zone. With horizontal slats on our grill, I use plumbing pipe foam insulation, the slitted kind, pushed onto the slats.

    Prius Grill Block.jpeg
     
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  15. onepoint21

    onepoint21 Junior Member

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    I've been driving my C about 75%+ highway miles and am seeing about 5.4 L/100Km on average so far. I'm a little sad that I haven't seen any fill ups below 5L/100, but I'm still working on it. I'm not an aggressive driver and keep my highway speed to 100km/h in 110km/h zoness. I always turn off ECO Mode when I hit the highway and use cruise control. Does anyone have any suggestions for improving my MPG? I checked my tires and filled them to around 40/38psi and haven't noticed any sort of difference. With the colder weather here on the east coast of Canada the A/C is on frequently to keep the cabin temp comfortable. Maybe I'm just expecting too much?
     
  16. Ashlem

    Ashlem Senior Member

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    The cold weather is going to affect your mileage, partly because the hybrid engine likes its warm weather, and partly because you probably like warm air too, so you'll be drawing heat into the cabin as well, forcing the engine to run more to maintain its heat. Technically it affects all cars, but it's much more noticeable in the prius because of its higher mpg. A 10% drop from 50 mpg to 45 mpg is going to look worse than 25 mpg to 22 mpg.

    Another factor may be how hilly your commute is. If you're going up and down constantly, that also affects your mpg versus a long flat section of road, especially while on cruise control as the car then speeds up to maintain its speed while going uphill.

    Using the heat or a/c is also going to affect it, though eco mode helps alleviate that part some. Of course you then have to get used to the sluggish response from the accelerator.

    My advice is to not worry about it too much. Worst case scenario, you're still getting better mpg than every non-plug in vehicle out there, unless you drive way over the speed limit regularly.

    I was getting 42-44 mpg in the winter time using winter tires (Michelin X-Ice XI3), but in the summer I was averaging 56-58 mpg regularly.
     
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  17. NatalieS

    NatalieS New Member

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    Great, thank you! I will look for that procedure.