1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Help!! Past 4 days nothing but gas engine use

Discussion in 'Gen 2 Prius Fuel Economy' started by BIGGDOGG, Jan 22, 2008.

  1. BIGGDOGG

    BIGGDOGG New Member

    Joined:
    Jan 1, 2008
    298
    0
    8
    Location:
    Morristown,NJ
    Vehicle:
    2008 Prius
    I have about 2000 miles on my 08 prius, Read all the posts about how to get great MPG. Usually when I am alone I don't use the heat. This saturday morning I got in the car and drove to the gym. usually I am able to go in electric mode till i get to 15-20mph. but for some reason everytime I try to just give alittle acceleration the gas engine kicks in.. It has been like that for 4 days now. Whats going on?? It got real cold here in northern NJ this last couple days around 20 degrees. But still I have always been able to electric drive it a little before the gas kicks in. But since saturday I haven't. Yesterday I had to drive it a little more that usual and I did notice it went into electric mode as I drove about a mile down a road, then once my speed was at 38 the gas kicked in.
    But I am still worried.
    Do you think it is because it is just really colder than it has been outside/more wind than usual?

    I am picking up some pipe insulation to block off the grill tonight. But still Why can't I drive in electric mode?

    Any help would be greatly appreciated....
    I really don't want to bring it to the dealer.
     
  2. Ichabod

    Ichabod Artist In Residence

    Joined:
    Jul 21, 2006
    1,794
    19
    0
    Location:
    Newton, MA
    Vehicle:
    2006 Prius
    Cold weather + short drives = more engine running and lower MPG.

    For a couple weeks here it was pretty cold and I did nothing but short (<1mile) drives, and my MPG was down to ~38! Warmer temps and longer drives always help. If you have errands to do, drive to the farthest place first. If you're driving by yourself to some place that's reasonably close and you don't have to carry a lot, ride a bike and your fuel economy will improve :)
     
  3. BIGGDOGG

    BIGGDOGG New Member

    Joined:
    Jan 1, 2008
    298
    0
    8
    Location:
    Morristown,NJ
    Vehicle:
    2008 Prius
    I hear ya, it has been cold hear before. I just never had my engine act like this so I am real worried.
     
  4. bestmapman

    bestmapman 04, 07 ,08, 09, 10, 16, 21 Prime

    Joined:
    Apr 8, 2007
    1,289
    242
    3
    Location:
    Kentucky near Cincinnati, OH
    Vehicle:
    2021 Prius Prime
    Model:
    Limited
    If you haven't read about the warm-up cycles, read this. It sounds like to me, that you are not getting to stage 4 like you used to.
     
  5. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    7,663
    1,037
    0
    Location:
    United States
    Vehicle:
    2004 Prius
    Model:
    N/A
    The engine running is normal when it's cold out. *Don't* block the radiator unless you have some way (scangauge, etc.) to monitor engine temperature.
     
  6. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
    Staff Member

    Joined:
    May 11, 2004
    14,816
    2,496
    66
    Location:
    Far-North Chicagoland
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    I'll admit that my first response is a little snide: how many winters in your Prius are you comparing this behavior to?

    Then I will tell you to calm down. Even with my blocked grill and four winters' of experience I can tell you that you are over-reacting. This happens when it gets cold. Block the grill and take long drives; you will see stealthing again.

    But yes, the engine runs more and the mileage drops. Check the >>Current Mileage<< link in my signature for proof. When it gets below freezing, I'll take any "engine off" I can get and they are fewer and farther between.
     
  7. BIGGDOGG

    BIGGDOGG New Member

    Joined:
    Jan 1, 2008
    298
    0
    8
    Location:
    Morristown,NJ
    Vehicle:
    2008 Prius
    I don't have a way of scanning the temp. I was only going to block the bottom half anyway for now till it gets a lil warmer.. What do you think?
     
  8. nerfer

    nerfer A young senior member

    Joined:
    Mar 1, 2006
    2,505
    232
    28
    Location:
    Chicagoland, IL, USA, Earth
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Two things, yes it runs more in cold weather like the others have said, and if you're taking short trips and trying to use the battery it could also be that your battery SOC is low, so it needs to recharge the battery, making it more likely to run the engine even when warm.

    Which brings me to the second point - I'm not sure if I'm reading your post right, but you shouldn't be trying to use electric power exclusively. Electric power comes from the battery which comes from the regenerative brakes which comes from forward movement which comes from the gas engine. (The battery can also be charged from the generator directly from the engine, but it's not a lot better). Each step loses some efficiency, so it's more economical to use the gas engine directly for normal acceleration. Save the electric power for extending a glide with a warm engine or when heavier acceleration is needed. Your MPG will go up.

    A recent trick I've read about and experimenting with a bit since my commute is so short, is to put the car in neutral whenever coasting during the first mile of driving. You can't recharge the battery while in neutral, so it's certainly not effective to use full-time, but the MPG does improve for the first 5-minute bar, which is about all I have on my commute. I'm still getting 45 mpg on this tank, but that includes occasional longer trips. Last year I was getting maybe 42 mpg in weather like this and that was on a longer commute. (My Prius lifetime average is 49.6 => 50's in the summer).
     
  9. nerfer

    nerfer A young senior member

    Joined:
    Mar 1, 2006
    2,505
    232
    28
    Location:
    Chicagoland, IL, USA, Earth
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    I think that's fine. It's only when the temperatures get into the 50's (Fahrenheit) that you need to monitor how much is being blocked, particularly on trips longer than a half hour. Read efusco's warning in that regard.

    If it's below freezing, you should be able to block the whole thing safely. I block the top and 3/5ths the lower, and leave it for the winter. But then there's the risk of forgetting about it when it finally does warm up.
     
  10. qbee42

    qbee42 My other car is a boat

    Joined:
    Mar 2, 2006
    18,058
    3,073
    7
    Location:
    Northern Michigan
    Vehicle:
    2006 Prius
    Yes, it's the cold affecting your mileage. Btw, 20 degrees is not even close to really cold. We go to the beach when it hits 20!

    Tom
     
  11. voltman

    voltman New Member

    Joined:
    Jan 22, 2008
    6
    0
    0
    Location:
    new york
    Vehicle:
    2008 Prius
    :cool:It could be in the cold batteries lose efficeiency.Bad idea blocking the radiator.
     
  12. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    7,663
    1,037
    0
    Location:
    United States
    Vehicle:
    2004 Prius
    Model:
    N/A
    I think gaining a few MPGs while incurring some risk of burning the valves is a poor tradeoff. But that's just me :_>
     
  13. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

    Joined:
    Apr 13, 2004
    15,140
    611
    0
    Location:
    South Puget Sound, WA
    Vehicle:
    2013 Nissan LEAF
    Model:
    Persona

    block it all. your avatar is two cars buried in snow... its more than cold enough that you have practically, next to barely anything at all to be concerned with.

    i block everything up to 50ºF...have been doing it for more than 2 years...
     
  14. BIGGDOGG

    BIGGDOGG New Member

    Joined:
    Jan 1, 2008
    298
    0
    8
    Location:
    Morristown,NJ
    Vehicle:
    2008 Prius
    I am confused now, alot of people are telling me to block the grill and some are telling me not to do it. It isn't a permanent blocking, I will take the foam out when it nears 40 degrees. as for now it is around 20 degrees and 10 with the wind chill....
     
  15. diamondlarry

    diamondlarry EPA MPG #'s killer

    Joined:
    May 20, 2007
    559
    12
    0
    Location:
    Elkhart, IN
    Vehicle:
    2007 Prius
    I went all last summer with everything but the bottom two slots stuffed with pipe insulation. According to the Scanguage, the temp never rose above 195F. Most of the cooling effects come from the lower slots in the grill.

    By using nerfer's coast-in-neutral technique I have gotten 50 mpg for my first 5-minute bar on numerous occasions.

    The colder it is, it seems that it takes less pedal pressure to kick in the engine on take off.
     
  16. JimN

    JimN Let the games begin!

    Joined:
    Nov 26, 2006
    7,028
    1,116
    0
    Location:
    South Jersey
    Vehicle:
    2010 Prius
    Model:
    V
    I run with the top blocked all year. I have one open "slot" in the bottom now. I have yet to hear the fan turn on and have the utmost confidence in Tony S., E. Fusco, and others. With the grill blocked this chilly month I now have 49.0mpg & 49.3mpg tanks which are below my 51.1mpg lifetime average. I don't expect the blocking to improve the lifetime average but I do expect to maintain it. I'll leave the temp set at 73 and turn the fan on low after 5 minutes or so to get heat from the left vent. The batteries aren't as efficient if they are too cold.
     
  17. nerfer

    nerfer A young senior member

    Joined:
    Mar 1, 2006
    2,505
    232
    28
    Location:
    Chicagoland, IL, USA, Earth
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    A lot of people are telling you to do it, one established person is recommending only doing it with a scangauge or CANview attached, and one unknown person (first post) is saying it's a bad idea but doesn't elaborate.
    As long as you don't fully block or if you unblock when the temperature gets in the 40's and above, you have nothing to worry about. Assuming you don't make 5-mile uphill climbs with a heavily loaded car with the front wheels spinning in the snow. Then the engine could get pretty warm no matter the outside temperature.
     
  18. pewd

    pewd Clarinet Dude

    Joined:
    Jan 28, 2007
    331
    1
    0
    Location:
    Dallas, Texas
    Vehicle:
    2007 Prius
    Why is it a bad idea? Support your statement.
    Numerous folks here block their grills with good results.
    Why do you disagree?
     
  19. N3FOL

    N3FOL Member

    Joined:
    Dec 2, 2007
    891
    16
    0
    Location:
    Stewartstown, PA.
    Vehicle:
    2008 Prius
    +1.
     
  20. BIGGDOGG

    BIGGDOGG New Member

    Joined:
    Jan 1, 2008
    298
    0
    8
    Location:
    Morristown,NJ
    Vehicle:
    2008 Prius
    Thanks again you guys, I drove the car more yesterday (RAN MORE ERRANDS) it seems to be ok, I was just freking out I guess. Tonight I will be blocking the lower grill (That is if I can find the pipe insulation).