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Which hybrid system functions better the winter between Toyota and Honda. I live in Canada Quebec...

I heard that the Prius was dropping of 10mpg in winter, is it the same thing for the civic (2006)?


thx
 

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SuperCharged said:
Which hybrid system functions better the winter between Toyota and Honda. I live in Canada Quebec...

I heard that the Prius was dropping of 10mpg in winter, is it the same thing for the civic (2006)?

thx
Tough call. In winter, the Prius will keep its engine on longer to keep warm, but it will allow it to turn off eventually, as long as you don't have the heat on full blast. I know the 2005 and earlier Civics would leave the engine on all the time if you wanted any measurable amount of heat at all; but with the redesign, I hope it has an electric heater in the 2006. It's probably a wash.

Just pick based on which car you like better. (As they'll probably get about the same mileage.)
 

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The current IMA relies on the 12-volt battery and a traditional starter when you turn the key in the extreme cold. (That may not be the case with the 2006 version.) With HSD, it uses the 200-volt battery-pack and the 10kW motor. So there's absolutely no contest which has less of a struggle starting. Prius has a huge advantage.

As for MPG, all vehicles take a hit due to a wide range of factors... like winter-formula gas. You simply cannot avoid that. How much for each is the question.
 

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Hi SuperCharged,

My experience with a non-Hybrid (SL2) car is that it gets 32 MPG in 85 to 95 F weather and 25 MPG in 0 to 10 degree weather in mixed highway and side street driving. Similar to what you said you are hearing for the Prius. I think this is pretty typical of allot of cars.

One advantage to the Prius over the Honda is that the Prius has a thermos bottle for the coolant. When the car is turned off, the coolant is pumped into the thermos bottle. So, it should be able to save gas by retaining coolant heat.

Now if you used synthetic oil, and the Prius had a plug in heater for that coolant and bateries, the Prius might be the first practical personal car for Siberia. Where people bring the batteries indoors and drain the coolant for overnighting the car.
 

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Hi DanMan32,

I have heard that coolant draining is done in Siberia from coleagues at work who grew up there. The problem is not so much to do with engine cooling, The Siberians removed the coolant from the engine to avoid cracking the block when the coolant freezes at 50 below 0 F overnight.

If there was a plugin heater in the Prius coolant thermos, then the Siberians would not need to drain the coolant from the engine. The Prius would do that for them. And one would think it would be easy to keep the coolant warmer than 20 below 0, in the thermos.

As far as the need for coolant, my guess is its needed in the sub 20 below weather in rural areas. The roads might require slow driving, and sometimes allot of engine power to get through drifts and high snow on the road. Again, that is at slow vehicle speed. The iron engine block in these cars have a cavity where the coolant normally is. This cavity can act as insulation without coolant. The only way for heat to get out of a typical car engine if not by the coolant is by the thin web of metal at the top of the block and bottom of the cylinders, and the oil in the oil pan.

Cars also do not coast well in cold weather as the rubber tires are stiff. So, the engine is always pushing. I imagine after a couple hours at 20 below of slow driving on snowy roads, the engine is going to be close to overheating.

If the car is never going to be driven at a temperature above 20 below, I imagine one could make the engine without a cooling jacket and exposed to the outside. Then conduction cooling might work. Of course these cars would be useless for three quarters of the year in Siberia, and all of the year most other places.
 

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donee said:
Hi DanMan32,

I have heard that coolant draining is done in Siberia from coleagues at work who grew up there. The problem is not so much to do with engine cooling, The Siberians removed the coolant from the engine to avoid cracking the block when the coolant freezes at 50 below 0 F overnight.

If there was a plugin heater in the Prius coolant thermos, then the Siberians would not need to drain the coolant from the engine. The Prius would do that for them. And one would think it would be easy to keep the coolant warmer than 20 below 0, in the thermos. . .
I think there's a bit more work to be done before you can feel safe about this. If the coolant is not circulating, the heater might keep the coolant in the thermos warm and toasty, but the coolant in the block would be just as prone to freezing (and block-busting) as before. So you need a circulation pump (or you need to power the one already in the Prius). The thermos pump in the Prius might not be rated for overnite continuous use (its usually only used briefly during start-up and shut-down).

Finally, once you have this all set up, you'll still be annoyed the day an ice covered tree brings down the power lines to your house! So you need a UPS or an alarm to tell you to go out and drain the Prius.
 

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I was half joking about not having coolant under running conditions in Siberia. I am sure though that there is an ambient temperature where the engine could run cool enough. However, part of the cooling system's job is to regulate the engine's temperature for optimum performance. That's why there's a thermostat.
Which brings another point. Must be a pain to drain both halves of the cooling system in a non-prius system: the block circulation, and the radiator circulation.
 

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Uhhh, you ALWAYS need coolant, even in the coldest of weather.

That's because there's FIRE in those cylinders! Think about it, without coolant to carry the heat away from the cylinder walls, eventually, it would get so hot, you'll start taking damage to to things like rubber like rubber rings, seals, and wire harnesses.

Even in the wintertime, your catalytic converter's insides can get so hot it's cherry-red, and that thing is several feet away from the engine.

You have to have something to carry that heat energy away from the engine block.
 

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Wow! This thread got hijacked.

Ok, IMA and HSD/THS are very different animals. Speaking strictly technically, all vehicle take a pretty good mileage hit in the winter as john1701a had stated earlier. That is unavoidable. However we don’t notice it that much because as fall weather comes upon us in the more temperate parts of NA, we don’t just wake up one day and notice that our fuel economy has dropped 10 mpg, but we see the change gradually over a number of months until we reach the coldest month for our area. I hope you see what I mean.

You choice of vehicle needs to be based more upon your personal taste rather than winter mpg performance, especially considering that winter mpg performance is decreased for all vehicles.

The Prius does have the advantage of having the hot coolant storage reservoir, which is unique to the HSD design. The reservoir is there mostly to help boost engine temperature and help in speeding up catalytic converter operating temperatures from cold start, so that lowest possible emissions can be achieved as quickly as possible without requiring the engine to run continuously for many minutes getting the system up to temperature. But the added benefit is that cold starts in the winter are less cold for this particular engine system and you will get cabin heat faster than many conventional vehicles.

The Honda just doesn’t have this system. If you think this is of benefit to you for your usage, than the Prius is probably a stronger candidate. But in other areas of hybridization, these two vehicles are also very different. Not all hybrids are created equal or identical.

Please read our other posts here to get a better understanding of other aspects of this vehicle.
 
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