Hypermiling strategies for a new 3rd gen Prius owner

Discussion in 'Toyota Prius Family' started by swineone, Apr 22, 2015.

  1. swineone

    swineone Well-Known Member

    Hello everyone,

    I'm a long time user here but I have been away for around 5 years now.

    Ever since that time, the Prius was released in Brazil, and I've been eyeing one ever since its release, to replace my wife's Fit (which was previously mine). A few weeks ago I found a used one, model year 2013, with about 27k miles, in very good condition and at a good price relative to its supposed market value. As a result, my wife is now the proud owner of a Prius -- one of the few hundred, probably less than a thousand, that were sold in the country since 2012.

    Thus I'm looking for a general strategy for hypermiling the Prius (when my wife lets me drive it, that is). So far I've read most of the pages in Hobbit's web site, and from there I gathered that a good strategy for low-speed driving is to pulse at the engine's sweet spot, which is around 1500 rpm/15 kW output (I'm using an ELM327 WiFi dongle plus EngineLink for the iPhone and iPad for instrumentation), and then glide using a light touch to the throttle pedal, trying to get close to zero on the HSI.

    As for highway driving, I haven't had the opportunity to drive the Prius on the highway yet, but I understand I should try something similar, but replacing a glide by warp stealth, which is well described in Hobbit's web site. I've also read about the so-called super highway mode, but I'm not sure if I should try it.

    I'd like to ask if I got the gist of it, and if anyone would like to point me toward other techniques that I should be aware of.

    Also, I have a couple specific questions.

    I've cycled through all the possibilities I've found on both displays (the black and white one with the HSI, and the color touchscreen with the energy monitor), but I haven't found a way to display the current trip's average MPG (since the car was started), or the instantaneous MPG -- I've noticed the bar chart near the speedometer, but I'd rather have a numerical display. When the car is powered down, some information is displayed on the black and white display, including the current trip's average MPG, so the car definitely keeps track of that information, but I haven't found a way to display it while I'm driving. It appears that both the current trip's average MPG and the instantaneous MPG used to be displayed on the touchscreen display of the 2nd gen Prius, but is it correct to say it's gone in the 3rd gen?

    Also, when I say MPG above, I actually mean L/100 km, which is the default unit displayed on our Prius. I've grown used to MPG as a fuel consumption unit, and so I've searched for a way to change the unit from L/100 km to MPG. Having gone through the settings menu on the black and white display, I didn't find a setting that changes the fuel consumption unit. Has anyone found a way to change it?

    Finally, what should I aim for with regards to the battery number of bars/SoC? At first I was trying to keep it close to the bottom, with the reasoning that I should leave as much headroom for charging the battery as possible. Obviously I understand that I shouldn't forcefully charge the battery, since the conversion efficiency from mechanical to electrical and back to mechanical energy is rather low, but the point is that if I suddenly need to brake, there should be headroom for charging the battery. On the other hand, it appears that this coaxes the car into more aggressively charging the battery, and given the issue of conversion efficiency, this strategy might be a net loss. I've read some people here try the opposite -- keeping the battery SoC as right as possible. So what should I aim for?

    Thanks in advance to anyone who takes the time to clear up my doubts above.

  2. RedylC94

    RedylC94 Well-Known Member

    I agree about the low-resolution bar chart displaying instantaneous mpg. It leaves a lot to be desired---yet occupies more area than a suitable numerical display.

    The programming seemingly tries hard to maintain a state of charge corresponding to 6 "bars " most of the time, at least in my Prius. There's probably no reason to fight it, with minor exceptions. Six is good. Starting from that level, you still have enough "headroom" for any reasonable circumstance except descending a mountain, and still can go about a mile (or 1.6km) EV at low speed on level terrain.
  3. fuzzy

    fuzzy Mild hypermiler

    Gen3 never had a live MPG display for the current trip. (The summary you see at shutdown was added in the 2012 midcycle refresh.) If you want to create one, dedicate TripA or TripB to this function by resetting it every morning or every trip. I use TripA for daily MPG, TripB for Tank MPG.

    Or create a current MPG display on your dongle/ipad/iphone combination. I have one on ScanGauge-II, but don't commonly use it.

    I haven't heard of any Gen3 that could switch between MPG and L/100km. While U.S. and Canadian models can switch the speedometer (only) on the fly, all other displays seemed to be fixed to imperial or metric units at the factory.

    Absent driver finagling, the car aims to maintain the battery at 6 (out of 8) bars. I don't recommend fighting it.

    Super Highway Mode is much less applicable to Gen3 than it was to Gen2. I don't bother with it.
  4. swineone

    swineone Well-Known Member

    Thank you everyone for the responses, they're very helpful (even if not what I expected).

    About the hypermiling strategies, is it a consensus that pulse and glide on the city, and pulse and warp stealth on the highway, are the best strategies, or is there something else I should try? I recall having read somewhere on the forum that Wayne suggests accelerating from a start using the EV for the first 15 mph or so, before engaging the ICE?
  5. EdwinTheMagnificent

    EdwinTheMagnificent Legend In His Mind

    That is what I've been doing whenever I can. Depending on the grade ( and your patience) you can get up to 20 MPH (33kph) or more in EV before the ICE starts. Just always remember where your electricity comes from. Gasoline.

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