OT: Hybrid cars

[guy keren]

(if you top-post, so will I!  ;)


driving the "old prius" myself (it's actualy the 2nd or 3rd generation 
of prius - but who's counting? :) - a few observations:

- the car has its algorithms - but you can "interfere".
   - when driving fully down-hill, the car usually turns the engine off, 
regardless of EV mode. this is most noticeable when you go down hill at 
a high speed (70kmh and above). just get your foot off the accelerator...
- when going down hill, sometimes the prius decides not to turn off the 
gasoline engine. in these cases, moving to 'B' causes it to turn off the 
gasoline engine (while also avoiding the car accelerating too much). i 
use this feature often when leaving home.
- the amount of gasoline the card will use varies greatly with the 
driving style and the speed of driving.

   some surprising observation: when driving through an "accordion pkak" 
(where you keep accelerating to 30-50kmh and then deccelerating back to 
10-20kmh and so on) - if done correctly, the Prius consumes the same 
amount of fuel per km as it does when driving at ~95kmh fixed speed on a 
flat road.

don't be so hard on the engineers behind the prius - just learn to play 
along with them.

--guy

On 09/15/2013 05:31 PM, Orna Agmon Ben-Yehuda wrote:
> Hi Mord,
>
> You are looking for something like this:community:
> http://www.kml.co.il/Models/%D7%98%D7%95%D7%99%D7%95%D7%98%D7%94_%D7%A4%D7%A8%D7%99%D7%95%D7%A1
>
> But you are right that hybrid cars have a lot of user-visible algorithms
> in them, and I think this makes it interesting to reverse-engineer.
>
> I think the most important division of hybrid cars is if the electric
> engine can be a stand-alone (like Toyota and Lexus) or is just a helper
> (like Honda Insight). A stand-alone electric motor will reduce your gas
> consumption in traffic jams, and a helper engine will give you
> additional boost when needed (instead of getting a larger engine to
> begin with).
>
> If you are looking for real efficiency, you want a small car with a
> hybrid stand alone engine, which is what the Toyota Yaris gives you.
>
> However, you also need to look into the algorithmics of the car. For
> example, the older Prius (2005-2009) would charge its battery when you
> are standing, just because it got empty (in case you want to boost your
> 1.5L engine soon). The B (Break?) gear is also interesting: The old
> Prius would just shift into low gear and actually consume more fuel, I
> believe, when you go down the mountain (and don't want to burn your
> breaks). However,  when you slow down or use the B gear, the Lexus
>   charges the battery more efficiently first, and only if it must -
> actually uses the breaks or other wasteful methods (at least in Eco mode).
>
> Another annoying piece of algorithm is that the old Prius refuses to run
> in ev mode (just electric motor) if you go above 40 Km/hour. This is
> rather stupid if you are just using your current speed to go down the
> mountain.
>
> Orna
>
>
> On Sun, Sep 15, 2013 at 1:42 PM, Mord Behar <mordbe0 at gmail.com
> <mailto:mordbe0 at gmail.com>> wrote:
>
>     Hi
>     I know that this is off-topic, but I really don't know who to ask.
>     See, I need a large pool of Linux-like brains that live in Israel
>     for this.
>     I mean, people (like me) who track gas liters and kilometerage, wear
>     and tear on the car, insurance and things like that.
>
>     Does anybody have numbers and experience to show how economical it
>     is to buy a hybrid car, and which one?
>     At what point of city-driving and non-city-driving does it pay to
>     buy a hybrid car? Gas is really expensive now, and probably just
>     going to go up. But hybrid cars are expensive too and the shelf life
>     of the battery is 5-10 years...
>     And I suppose that the terrain matters as well. In Jerusalem the
>     hybrid car will use more gasoline than in Tel Aviv.
>     Thanks.
>
>     P.S.
>     Mods, if you remove this message I totally understand, but could you
>     please point me somewhere else instead?
>
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>
>
> --
> Orna Agmon Ben-Yehuda.
> http://ladypine.org
>
>
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