Why Mileage Gets Worse in the Winter

Discussion in 'Gen 2 Prius Fuel Economy' started by TonyPSchaefer, Oct 30, 2011.

  1. Gen2_Accel

    Gen2_Accel Junior Member

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    Butane is added in winter fule- better vaporization at lower temps, but lower BTU.
     
  2. bisco

    bisco cookie crumbler

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    i love their lighters (y)
     
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  3. Ryan duerlinger

    Ryan duerlinger New Member

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    ‍♂️‍♂️‍♂️ It’s pretty common knowledge or so I thought that this is NORMAL. Don’t over diagnose your cars guys.

    it’s colder in winter taking longer to warm up your vehicle. Usinging the gas engine more than normal.
    Also running the heater will decrease mileage. Not the same as the ac but if your engine has to heat the cab and cycles on and off that uses gas. . .

    if your serious about your mileage get a block heater from Toyota Canada or aftermarket and use the to heat the block in the morning hours before use of vehicle to reduce or eliminate running the gas engine to warm up vehicle.

    I’m not saying not to do regular maintenance but don’t look for problems that DONT exhist.

    I have a brand new engine plugs wires thermostat hybrid battery o2 sensors and cat. Still gets less in winter.
     
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  4. Mendel Leisk

    Mendel Leisk Sunday driver DIY’r

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    I don’t know about “eliminate”, but it does allow me to reliably exit the garage and get about 100 yards in EV Mode. Which I usually want to do, just to be less noisy. Without the block heater, there’s no chance of EV Mode.

    Engine kicks in once you exceed ~15 kmh and regular warm up commences. Warm up is accelerated; you’ll get engine shut down at stops within a couple of blocks, in particular if you shut the heat/vent system off. Sometimes just lowering the h/v temp setting will do the trick.
     
  5. Ryan duerlinger

    Ryan duerlinger New Member

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    Exactly.
     
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  6. chronon

    chronon Active Member

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    simply disconnecting the snorkel allows warm engine compartment air to be drawn in .. and brings up the mpg .. then if you can bring hot air from above the exhaust/ head area .. you can bring it up a smidge more ..
     
  7. George W

    George W Active Member

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    Down here in South Texas I have just the opposite problem. Our high heat/ high humidity Summers sap my fuel economy. The winter months, mild as they usually are, gives me two to three miles per gallon more
     
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  8. chronon

    chronon Active Member

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    I guess because using the AC alot .. yes here in FL have similar problem.. maybe not as hot depending .. but certainly gotta be everybit as humid .. like a tropical rain forest with daily rain .. seems every year is a 'new weather pattern' .. like someone playing with global weather .. not much energy in water vapor though .. u can actually gain some mpg with intae addition of cold water vapor mist (like from an ultrasonic humidifier) -- those particles (like a cloud) are probably smaller than humidity in the air though .. ...
    the 'vaporized' gas can really improve combustion efficiency -- just heating gas before combustion shows the increase .. like using heat from the coolant to warm the gas going to the TBI ... or heating the intake manifold .. difficult with the tiny elbow room in the prius engine compartment ..
     
  9. George W

    George W Active Member

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    I don't understand how I would implement this on my Prius
     
  10. chronon

    chronon Active Member

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    Well when i had my gen 1 prius .. and gas was like 3 or 4 $ /gal .. i took a fogging unit .. hooked it up to 12 v .. had a switch wired so i could flip it in the car .. and about a cup or pint of water the fogger was in .. i think it was a vitamin bottle .. drill hole in top .. insert ~1/8" ID plastic tube and route to air intake/ preferably manifold .. seal with your adhesive/silicone choice .. .. i did see a 5% mileage improvement ... just make sure the damn water is BElOW the intake manifold so that in the event of a spill / siphon... the water cant get sucked into the intake manifold directly ..

    the harder part is the water level .. u need to mke a float system because the water level likes to ride about a cm or so above the ultrasonic level .. and so when it gets used up and needs more water an above container needs to feed the 'cloud chamber' for the proper water levvel ..

    there r utubes of this being demonstrated (engines running with /on water vapor )
     
  11. Karyy

    Karyy New Member

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    How long do you take to heat up your car? Just wondering, I heard idling the car is bad too. After turning on the car, do you turn the heat on, or just wait a few minutes for the engine?
     
  12. Isaac Zachary

    Isaac Zachary Active Member

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    So far my experience with the Toyota block heater for the past two winters is fairly lame. It doesn't really put out enough heat to make much of a difference. Sure it helps a little, but is barely noticeable. I still get 20mpg around town in my Toyota hybrids. I think it's main purpose is to prevent the coolant from freezing at temperatures down to -60°F. It seems to keep the engine about 30°F warmer than ambient temperatures, and that's about it. At -40°F the engine is still -10° when starting with the heater plugged in.

    What I'm going to do is what I've done on past cars: get a 1,500W or better circulating tank heater (I have 20amp outlets both at home and at work so I'm contemplating getting a 2,000W heater). 15 minutes with one of these will make the engine warmer than all night with the Toyota block heater. Or you can plug it in for an hour or two and get nearly operating temperatures (140°-160°F) in sub-zero weather.

    Since the heat energy in gasoline and electricity is about the same per dollar I've also contemplated one of those gas fired engine heaters. Of course the initial cost is much higher and there's a greater chance of draining the 12V battery. But at least I could heat my engine anywhere I park without the need for an outlet and cold-weather proof extension cord.

    I also want to wrap the exhaust and engine in mineral wool and put a heat exchanger on the exhaust post catalytic converter. Maybe that's too ambitious.

    I'm not sure if @Ryan duerlinger was referring to idling or to just get in and go and let it warm up that way. Either way, it's going to take longer to get up to operating temperatures in the winter. Personally I don't idle to warm up. But then when driving to work, even with the heater off, I end up at my destination with engine temps maybe at 120°F, if that. That can't be good for the engine either.
     
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