When its cold here, and i have the heater set to auto, maybe around 72 or 73, the motor will run all the time, even at stop lights. I've found, if you turn the auto off (just press the button on the steering wheel) the motor will turn off, shift over into neutral, and then turn the heater back on again. The motor will not come back on until you shift into drive when you're ready to move again. I just wonder, am i causing any harm doing this? I've went from an average of 35mpg to 39mpg just by using this technique at the stop lights, but i certainly don't want to ruin anything in the process!
No harm, just good energy management. Lots of us use similar techniques during the initial warm up to maximize efficiency.
hay giga, ever consider an engine block heater? it gets pretty darn cold in nebraska, right? I think Evan would agree, it certainly may help, and it wouldn't hurt!
GigaTigga, Try leaving the temp where it is but turn the "auto" off. Put the fan on one of the lower settings. Start up with the climate control off. After the 1st 5 minutes turn it on when running. If the ICE is still running when the car is stopped then turn it off. Since it is cold enough to be doing this, besides the EBH, the grill should be blocked.
I live in an apartment building, so ebh is out of the question at this point. Also i'm a little hesitant to block the grill, as in nebraska, we can have a day of 0 degrees and the next day have a high of 55. The way i do it seems to work, i just didn't know about the wear on the transmission shifting into neutral and drive all the time, certainly would dis-advise someone from doing that on a regular automatic transmission.
There is no mechaniacal shifting envolved (other than the movement of the shift lever its self). Only the algorthims used by the computers to control systems operation are changed. The 'transmission' does not change gears in the sense that a conventional transmission does.
Tricking the ICE to shutdown, bad idea? This is an interesting thought. Has anyone built or installed an ICE kill switch. I know that several people essentually use the EV switch for this. My question is: Has anybody made an actual ICE kill switch and what are the benefits/uses and drawbacks of this idea?
I installed one on my Saturn. It involved tapping into the fuel injector wiring and cutting power to the injectors. The engine would die almost immediately. I would think that the same setup I used would work on a Prius. Although, it would be interesting to see how much the Prius would freak out if you tried it.
If I have a choice of shivering at -30 C, or burning an extra cup or two of fuel, I'll burn the extra cup or two of fuel
Have you ever heard of Prius over-heat problems in winter? For me, never! If I were you, I block 100% of upper grill and 80% of lower grill on such conditions. As hschuck wrote, there is no ill effect shifting into N on stops. Please note that you'll save more fuel to do A/C off on coasting too. Ken@Japan
That's right. That's why I have adopted a slightly different technique to achieve basically the same thing: I leave the auto control on, and set the temperature to the second lowest setting (not the LO setting, but the lowest setting where the setting is indicated in degrees; in my case 16°C). Most of the time this allows the ICE to shut off almost as soon as when the climate control is shut off completely, and also when coasting. Then, as the ICE slowly warms up, I gradually increase the temperature setting just enough that it doesn't cause the ICE to run. I usually increase the temperature setting while waiting at a stoplight just when the light turns green, so that if I overshoot, and the ICE starts as a result of the setting, it would have started a second or two later anyway to accelerate away from the stoplight. For me personally, this is the best compromise between convenience, safety, comfort, and fuel economy that I have found so far. Oh yes, and long underwear, warm socks, and a warm sweater help too!
Its been done, and it freaks out pretty good I think hobbit tried this, there is a procedure in the training materials for pulling one of the relays (fuel pump I think) which causes the ICE to die but allows continued EV mode driving. Basically same as what happens when you run out of gas. Lots of nasty dash lights and codes but no obvious ill affects. Can easily cause you to run the HV battery down too far, which can be pretty big problem. Rob
Following method is not an ICE kill switch, but it sends a fake coolant temperature to the engine ECU, so that you can go any warming-up stages, like S2 or S4, at anytime. http://priuschat.com/forums/showthread.php?t=36342 (Please do it on your own risk! This hack might cause ill effects on your cold engine.) Ken@Japan
