Page 1 of 4 123 ... LastLast
Results 1 to 10 of 37

Thread: Temperature and Fuel Economy

  1. #1
    Senior Member
    Join Date
    Mar 2015
    Location
    Columbus, OH
    Country
    United States
    Posts
    250
    Thanks
    70
    Thanked 168 Times in 82 Posts

    Temperature and Fuel Economy

    I've seen discussion on here lately about colder temperatures affecting fuel economy. I just wanted to throw in my two cents worth.

    The setup: I've got a ScanGauge E that shows exact coolant temp. I live in Central Ohio, where it's been about 10-15 degrees F. I have an engine block heater that I use whenever I can (unrelated to this post, I just love my block heater is all ).

    The observation: With the cabin temp set to 68 to 70, and on auto, it eventually ramps up the fan pretty fast. If I leave it on auto, the fan speed stays high, and my coolant temp wont get up to 195F. If it's cold enough, the cabin fan blowing through the heater core pulls enough heat out of the coolant to prevent the engine from reaching full temp.

    It would seem to me that an engine not operating at its' optimal temperature, would use more fuel. Might be worth bundling up a little more, turning off auto temp, and lowering the cabin fan speed. Thoughts?


        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 44.1 mpg (US) ... 18.7 km/L ... 5.3 L/100 km ... 52.9 mpg (Imp)


  2. The Following 2 Users Say Thank You to wellswebdesign For This Useful Post:

    Eggman (12-20-2016),inuvik (12-20-2016)

  3. #2
    Moderator Eggman's Avatar
    Join Date
    Sep 2015
    Location
    Ohio ☼
    Country
    United States
    Posts
    2,853
    Thanks
    1,949
    Thanked 684 Times in 508 Posts
    Gathering data like this helps. Thanks - it all makes sense to me.

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 48.9 mpg (US) ... 20.8 km/L ... 4.8 L/100 km ... 58.7 mpg (Imp)


  4. #3
    Senior Member
    Join Date
    Mar 2015
    Location
    Columbus, OH
    Country
    United States
    Posts
    250
    Thanks
    70
    Thanked 168 Times in 82 Posts
    I suppose I should have said what temp it does stay at. Since it depends on outside temp, cabin fan speed, and how I'm driving, it seems to hover anywhere from 130 to 150. With the cabin fan lower, or off, it does get up to full temp.

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 44.1 mpg (US) ... 18.7 km/L ... 5.3 L/100 km ... 52.9 mpg (Imp)


  5. #4
    Moderator Eggman's Avatar
    Join Date
    Sep 2015
    Location
    Ohio ☼
    Country
    United States
    Posts
    2,853
    Thanks
    1,949
    Thanked 684 Times in 508 Posts
    Is your grill blocked?
    What are intake air temps?
    Can this be captured and graphed?

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 48.9 mpg (US) ... 20.8 km/L ... 4.8 L/100 km ... 58.7 mpg (Imp)


  6. #5
    Senior Member
    Join Date
    Mar 2015
    Location
    Columbus, OH
    Country
    United States
    Posts
    250
    Thanks
    70
    Thanked 168 Times in 82 Posts
    No grill block yet. I'm wanting to do it nice.

    I'm pretty sure the ScanGauge shows air intake temps, I'll have to find it.

    As far as I know, the ScanGauge doesn't capture it. At least not that I'm aware of. If I had the time, it'd make a fun Arduino project.

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 44.1 mpg (US) ... 18.7 km/L ... 5.3 L/100 km ... 52.9 mpg (Imp)


  7. #6
    Senior Member
    Join Date
    Apr 2016
    Location
    Minneapolis
    Country
    United States
    Posts
    120
    Thanks
    70
    Thanked 41 Times in 31 Posts
    When I worked at a dealership for 30 plus years, we all would just shake our head at any fuel economy talk in the winter months. Just be comfortable and whatever milage you get, is what you get. Bearings turn harder, longer warm up times, fuel can be different, rear defroster electrical load, it goes on and on.

  8. #7
    Senior Member
    Join Date
    Sep 2015
    Location
    Fredericksburg, VA
    Country
    United States
    Posts
    339
    Thanks
    70
    Thanked 83 Times in 58 Posts
    Quote Originally Posted by flatbroke View Post
    When I worked at a dealership for 30 plus years, we all would just shake our head at any fuel economy talk in the winter months. Just be comfortable and whatever milage you get, is what you get. Bearings turn harder, longer warm up times, fuel can be different, rear defroster electrical load, it goes on and on.
    Excellant point! Just told my wife, almost the same thing yesterday. She has a 2013 CMAX hybrid, and was bummed because her mileage is dropping.

  9. #8
    Senior Member Top_Fuel's Avatar
    Join Date
    Feb 2016
    Location
    Ohio
    Country
    United States
    Posts
    647
    Thanks
    293
    Thanked 402 Times in 203 Posts
    FYI... A Scangauge does show air intake temperature. It's usually one of the 4 gauges I have displayed on mine.

    As a general rule, I have noticed that the air intake temperature normally runs about 7-10 degrees above the ambient temperature. This car pounds the fuel when the outside temps are really cold. I can't imagine the mileage some of you guys are seeing who regularly drive in sub-zero temps!

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 51.6 mpg (US) ... 21.9 km/L ... 4.6 L/100 km ... 61.9 mpg (Imp)


  10. #9
    Administrator MetroMPG's Avatar
    Join Date
    Jan 2013
    Location
    1000 Islands, Ontario
    Country
    Canada
    Posts
    5,766
    Thanks
    1,683
    Thanked 1,450 Times in 895 Posts
    Quote Originally Posted by flatbroke View Post
    When I worked at a dealership for 30 plus years, we all would just shake our head at any fuel economy talk in the winter months. Just be comfortable and whatever milage you get, is what you get.
    Disagree! Too fatalistic for my liking.

    There are lots of things you can do to help minimize the cold weather fuel economy penalty, eg. off the top of my head:



    • Don't idle the car to warm it up.
    • Install & use a block heater (arguably extends engine life, too).
    • Make sure tire pressure is kept up (many people forget/don't know that pressure falls with ambient temps -- I see more cars driving around on half-flat tires in early winter than any other time).
    • Turn off the A/C compressor if you don't need it when using the "defrost" setting.
    • Make a partial or full grille block (how much depends on your individual circumstances; aerodynamic benefit as well as thermal management benefit).
    • Avoid doing many short trips where the vehicle never warms up fully; combine trips if possible.
    • Make sure snow/ice is fully cleaned from the car (can be a significant drag penalty at higher speeds - increases both frontal area and drag coefficient).
    • Use synthetic lubricants wherever possible, engine, transmission, etc. (viscosity is more stable vs. conventional lubricants which dramatically thicken in freezing temps).
    • Really pay attention to your highway speeds: aero drag is proportional to both speed as well as air density. You burn more fuel per each MPH increase in cold, dense winter air than in warm summer air.
    • Choose a manual transmission when buying. It avoids the extended warm-up penalty that automatics experience (forced higher engine RPM until a certain coolant temp is reached).


    OK, so doing these things won't permit anyone to match their summer MPG in the freezing cold, but they will help atleast keep the seasonal difference to a minimum.

        __________________________________________

        click to view fuel log View my fuel log 2014 Mirage base ES 1.2 manual: 54.0 mpg (US) ... 23.0 km/L ... 4.4 L/100 km ... 64.9 mpg (Imp)


  11. The Following 2 Users Say Thank You to MetroMPG For This Useful Post:

    Eggman (12-23-2016),Top_Fuel (12-23-2016)

  12. #10
    Senior Member fifteenwindow's Avatar
    Join Date
    Oct 2013
    Location
    Madison, WI
    Country
    United States
    Posts
    214
    Thanks
    137
    Thanked 79 Times in 57 Posts
    Adding a warm air intake shortens the time it takes to get your motor up to operating temperature, and it works very well with a grille block.


        __________________________________________

        click to view fuel log View my fuel log 2014 Mirage DE 1.2 manual: 53.1 mpg (US) ... 22.6 km/L ... 4.4 L/100 km ... 63.8 mpg (Imp)


  13. The Following User Says Thank You to fifteenwindow For This Useful Post:

    MetroMPG (12-25-2016)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •