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engine question

Discussion in 'Gen 3 Prius Technical Discussion' started by joeb24, Dec 24, 2009.

  1. joeb24

    joeb24 Junior Member

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    I just picked up my 2010 Prius IV. When I first start the car, the engine comes on. I thught only the electric motor is supposed to come on when first starting out? Any thoughts would be appreciated.
     
  2. jdcollins5

    jdcollins5 Senior Member

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    First, welcome.

    Normally the engine does not come on for about 10 seconds after you start the car. I think some heater settings such as defrost or high heat can cause the engine to come on early.

    Also, when you first start to drive, the electric motor will be used to begin acceleration unless you press hard enough on the accelerator to force the engine on.
     
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  3. DetPrius

    DetPrius Active Member

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    Congrats on the new car and Welcome to Prius Chat!

    The engine will come on initially as it is designed to minimize emissions and it needs to warm the engine. If the temps are warm enough, you can press the EV button right after entering Ready state and it will prevent the engine from starting but that will not be available in colder weather, unless the engine and battery and already warmed up.

    You will find an enormous amount of information on this site so I suggest you check out the sticky threads and start looking at some of the other threads. There are many very knowledgeable folks here (I'm not one of them) that are willing to help but try to search for answers on your own first as so many questions have already been answered.

    Again, welcome!
     
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  4. David Beale

    David Beale Senior Member

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    To be totally accurate, about 10 sec. after you take the car to "ready" (on) the engine will start and run the "cat warmup" cycle. It does this -every- time you go to "ready", whether the engine is warm or not. You can, under certain circumstances, temporarily delay this action by using "EV" mode.

    If you don't have the climate control on (A/C) and calling for heat, the engine will shut off after about 20-30 sec. It will restart if you depress the accelerator far enough.

    Yes, the car will start moving on battery power only, if you are gentle enough. It is, however, a gasoline powered car, so eventually the engine will have to run.
     
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  5. Blind Guy

    Blind Guy New Member

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    * ALL of the advice here is EXCELLENT! Let's say you are starting your car after it's been parked for some time and the engine is Cold Soaked, this will require the engine to start when the car is first started, due to the need for it to warm itself and the Catalytic Converter. You can sometimes delay the engine starting by pressing the EV button, but only if the Hybrid Battery has a sufficient SOC (State of Charge), and this will ONLY delay the engine from its need to start.

    If, on the other hand, you start the car after it's already warmed up and the Hybrid Battery is in a good SOC, it will not be necessary for it to start until enough Hybrid drain causes it to light to recharge the Hybrid Battery.

    Once the enginne has been warmed, and again, the Hybrid Battery has sufficient charge, whenever you come to a stop, the engine will cease running until enough throttle, speed or low Hybrid Battery SOC demands it to come to life.

    There are many factors that can alter these general rules, like, A/C selection and heater temperature settings can force the engine to come on, even though it's sufficiently warm, as well as other demands that can cause the engine to start.

    Remember, the Electric Motor is working in conjunction with the Gasoline engine, thus the term Hybrid, but the Electric Motor simply supports the Gasoline engine, and the Gasoline Motor MUST run to charge the Hybrid Batter that runs the Electric Motor.

    Welcome, and Happy Priusing!

    David (aka Blind Guy)
     
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  6. joeb24

    joeb24 Junior Member

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    Thanks to all of you for the advice! The day after I picked up the car from the dealer, I took a 300 mile trip XMAS trip. After stopping at rest stops, I noticed that when I started the Prius, onlty the electric motor came on at first, then the engine kicked in upon accelerating. So things seem normal. I guess, initially, at the dealership and shortly thereafter, the Hybrid battery did not have sufficient charge.

    By the way, the Trip Computer indicated I got 52 MPG for the 300 mile trip. My speed was between 55 and 65 MPH, and I was trying to be gentle on the gas pedal, coasting downhill when possible. How accurate is the MPG indicated by the Trip Computer?
     
  7. jdenenberg

    jdenenberg EE Professor

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    The MFD in the earlier models (2004-2009) tended to be a little optimistic in MPG (by about 4%). Keep good records and compute the MPG manually to see for yourself.

    JeffD
     
  8. EWRoberts

    EWRoberts Junior Member

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    I got my Pruis in August, with one mile on it. I have driven it seventeen thousand miles since then, and have not found one thing wrong with the way it was put together. I am really impressed with Toyota. The mileage I get is five percent less than the display claims, and the actual speed is two or three percent lower than the display speed.

    It gets 49 mpg overall, 45 when it is cool out. The car is a good enough snow car, and has good enough acceleration.

    There is no use trying to manage the engine operation, cause the computer does that, and the pick up is fine, but the sounds are not what I am used to, so I think it is sluggish starting out, but that is not the case. The electric motors take the hole shot, and the engine chimes in.

    I became mezmerized watching the display, lol. I am glad it is a heads up display. I get the same mileage whether I am watching it or not, slow is better, every time.

    Enjoy, Eric.
     
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  9. AussieDave

    AussieDave New Member

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    Engine starting is dependant on so much.

    My normal standard state is to have climate control on, Auto headlights and Auto wipers on. Usually the last 5 minutes of my drive home are coming up a steep hill and the engine runs so I gues the battery is pretty charged up.

    Usually next morning my routine is to start the car, back out of the garage, get out and close the door and then reverse down the drive into the street where I stop, select D and drive of down the road. Usually the ICE does not start until about 200m down the road. It has become a bit of a competition with myself to see how far I can get before the ICE does start and that seems to depend on how the outside temperature compares to the setting on the climate control.

    I do not think the ICE starts up just to warm the catalytic convertor.

    David
     
  10. David Beale

    David Beale Senior Member

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    Actually the cat temp can be determined by the O2 sensor reading. There is usually one on the cat and its' output without the engine running can be used to determine when the cat needs warming.

    I am unsure if the GIII does it the same, but the GII -always- runs the engine when you put it into "ready" - subject to the EV mode being set. It's a programmed cycle to warm the cat and will run even if the cat is already warm (so the O2 sensor reading was probably not reliable enough - I know the cat O2 sensor has been used to detect cat overheating at least). I'm not sure exactly -why- the cat has to be warmed -before- the engine is needed for power. You would think it would warm when you actually needed the engine, but apparently you would be wrong. ;)

    Pearl will run the engine for 20 sec or so -every time- I put her into "ready". Even if I shut her off, then immediately put her back into "ready", regardless of the state of the A/C, coolant temp, etc. I don't have an EV switch so I can't comment on that variable.