One of the benefits of the hybrid system that I appreciate is that it seems to protect the internal combustion engine when cold. That the more powerful traction battery is able to crank the engine at higher speeds and the thermos (in the American version) can sometimes help a parked engine conserve a little heat have been well covered. I'm thinking of how the Prius seems to place very small demands on the engine when it's cold. In the winters here, I would often get a little too worried or frustrated asking my wife to drive her old Civic very slowly till the engine warmed up. I could feel the engine struggling when well below freezing, even with 0w-30 Mobil 1. I was worried about altered clearances or gaps between parts due to thermal contraction and expansion. Perhaps I was being too anal to worry about this. I would cringe when she would start up in the morning and being late to work, head out with a firm foot on the throttle. I haven't driven the Prius in the winter yet, but from spring and summer use it seems that this may become a non-issue with the Prius. It seems that when the engine is cold the hybrid system places very low demands on the engine. It runs the engine or ICE but also pulls from the battery for anything beyond very gentle acceleration. I haven't driven a Prius for more than a few days in the winter and don't have CAN-view. Can others with more data verify my conclusions? For years Toyota and other manufacturers have advised drivers to warm up an engine by driving the car gently. The hybrid system seems to use the battery to substitute for engine power when cold, enabling the driver to drive normally while the engine warms up gently. I hope that this is one more way in which the hybrid system will improve the longevity of the car.
After *SIX* winters driving a Prius in Minnesota, I can most definitely confirm that the system is more protective of the engine than anything else you have ever encountered... including a Prius in the warm season. Look at it this way, the battery-pack prefers the cold. It doesn't have to worry about getting too hot then. So more generous use of electricity in the winter is no big deal.
on my Classic the first 3 minutes or so will draw up to about 60 amps and the ICE will hardly rev up, most I see is about 1600 RPM. Once past that threshold the ICE will rev as normal but the first bit it's the cat coming up to temp and the retarded cam timing the sends a warm rich mixture in to the cat. I see a simular effect with the wifes 2k4 and CAN-view but the effect seems to me to be limited unlike the Classic. I'm sure those that drive a G2 with CAN-view will give more information on cold current draw till warm. Don't worry about a Prius in the cold it will prevent you from causing damage.
I was going to start a new thread on this but I think the Thermos is truly amazing!! Before this last 10 days I thought it was a "nice" after thought, but now I know better. I let my car sit for 10 days. I would guess that the thermos was at ambient temp for the night. I came home late in the day and the temps were in the mid to high 80's and started "Belle" up. The engine temp was low and after the dump from the thermos even lower. The really amazing thing is that it took me nearly half the route I usually go to work etc to get the car up to 161 degrees F. During the summer with or without the block heater this is unheard of. Last summer with the temps in late afternoon at 86-88, I was above 161 before I got out of my development (.3 mi) It took me almost 1.3 mi to get "Belle" up to operating temp. I will never discount the thermos again!! It works, it is valuable and not a minor contribution to the efficiency of the Prius!
as I don't have a thermos on the Classic I'm still using the umbilicle cord and this morning with 2 1/2 hours it had the ICE at 130F+ 56C for those that can convert and I was in S4 6 blocks from home. I doubt that the 2k4 with the thermos would do a lot better. If she could park it so that we could plug it in I'd install a block heater in it.
I see this every morning with CAN-View. When I just start driving, it's putting up to 80amps and never rev above 2000 rmp during warmup. To be fair, I never try to floor it when it's warming up.
<div class='quotetop'>QUOTE(hdrygas @ Jul 10 2006, 09:52 PM) [snapback]284235[/snapback]</div> Are you saying your commute is under 3 miles? (~1.3 * 2) Why not ride a bike? Disregarding that, how do you get such good mileage numbers on such a short commute? I'll agree though, the thermos is a good idea, one I didn't know about until I had the car.
<div class='quotetop'>QUOTE(Frank Hudon @ Jul 10 2006, 10:21 PM) [snapback]284258[/snapback]</div> Frank: With your record-setting heat wave, I bet you really scare the neighbors by still plugging in your car. The first winter I had the car, before I made the winter front, at -40 I can confirm the Prius is VERY eager to use the electric motor. True I have underground heated parking at my condo, but after parking for a few hours outside at a mall, I could easily dust other cars that were barely moving. Actually, at temps much below -20 C, there is always excess SOC. I really wish Toyota had used that charge to run supplementary high voltage heaters. Before the winter front I just about froze some parts off. jay
It's been amply documented over in the prius_technical_stuff yahoogroup that startup behavior does indeed propel you *solely* on battery for the first 30 seconds or so, while the retarded spark and richer mixture causes, as a listmember so aptly put it, huge flames roaring down the exhaust manifold to get the cats warm. Then things level out and become sane and allows the engine to start contributing useful propulsion. If you start up and immediately ream it, however, the engine *will* get a higher load placed on it right then, from stone cold, and that's probably a bad idea. . So when you start cold [or as cold as the thermos-pumping cycle leaves the block] you can go immediately but try to be gentle and NOT let the engine RPM increase at all for the first minute or so. It's not ready yet. If you listen carefully, you can hear a subtle shift in the running sound -- less of that metallic sort of noise in the exhaust that comes from spark retardation, perhaps replaced by a little bit of inverter whine as MG1 starts receiving a load. . _H*
<div class='quotetop'>QUOTE(hobbit @ Jul 12 2006, 09:59 AM) [snapback]284940[/snapback]</div> H That's a bad idea with any vehicle, not just the Prius j
<div class='quotetop'>QUOTE(john1701a @ Jul 10 2006, 04:40 PM) [snapback]284043[/snapback]</div> Does it help us, in the warm areas, you think, or is it worse for us? I am curious about this.
No, actually the battery pack prefers the same temperatures that we humans do. Maximum charge and discharge current is limited to about half of what it normally is when the battery's been sitting out all night in the cold. That's why it's good to swipe some of that heat being wasted from the engine anyways to warm you, warm the cabin, and eventually warm the battery too. Ohmic heating as you drive will also contribute, but a supply of warmer air into the duct helps.. . _H*
<div class='quotetop'>QUOTE(jayman @ Jul 12 2006, 06:47 AM) [snapback]284907[/snapback]</div> I've actually had one neighbour say "I thought you didn't have to plug in those hybrids" so I said nope you don't but I do just for the hell of it! Little does he know I gain about 3 miles to the gallon doing it. Ah life's little mysteries.
<div class='quotetop'>QUOTE(nerfer @ Jul 11 2006, 12:44 PM) [snapback]284552[/snapback]</div> No it is closer to 9 miles and 15-20 minutes to get from home to work 1.3 is where I slow down to make the second turn. The route is all under 35 mph but with 7 lights all in the last 2-3 miles of the trip. I am using the block heater for an hour and half and am up to 161 at about .3 miles when I turn out of the development I live in and go from 20 mph to 35. I cut the time of heating down from 3 hours winter pre heat. I am going to creep it down a bit more and see how short I can get it.
<div class='quotetop'>QUOTE(theorist @ Jul 10 2006, 08:25 PM) [snapback]283953[/snapback]</div> Are you saying that European version doesn't have thermos?
<div class='quotetop'>QUOTE(vlenac @ Jul 15 2006, 01:30 PM) [snapback]286880[/snapback]</div> only the NA Prius has the thermos. Or the bladder
I'm in New Zealand and have just bought a 2012 Prius alpha (=Prius v) imported from Japan. I like it. We don't have the temperature extremes that you have in the USA, but what are the thermos and the bladder?
congrtas and welcome! thermos stores coolant to keep it warm for the next trip. bladder is a rubber device in the gas tank to help with emissions, only in n/a. it was a nightmare, corrected on gen 3.
The bladder was used in Gen 1 and Gen 2 in the US (and maybe some other markets), kept liquid fuel and vapor trapped inside, and the remaining space in the tank held air and no fuel vapors (instead of filling with 11 gallons of vapor when the fuel was low). Gen 3 just has a more elaborate conventional EVAP/ORVR system instead. The bladder never bothered me in my Gen 1, though some people write as if they've been deeply traumatized by it. The thermos was used in Gen 2 in the US (and maybe some other markets), hot coolant would be pumped into it while the engine was running or just after stopping, would remain pretty hot for up to a couple days, and would get pumped back into the engine before starting next time. Kind of a neat idea. An expensive part located just under the left fender, easy to damage in a crash. Gen 3 did away with it, and instead added an exhaust heat recirculation system to heat the coolant quickly from the exhaust to speed warmup. People sometimes confuse that with the exhaust gas recirculation (EGR) also used on Gen 3, but those are two distinct systems.
