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How do I properly drive this thing?

Discussion in 'Gen 4 Prius Main Forum' started by Jbrow327, Nov 6, 2020.

  1. fotomoto

    fotomoto Senior Member

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    That's the cold start issue. The recommendation is to leave the gen 3 ice running IF it was a COLD start. If the ICE is warm, there's no need for special procedures.
     
  2. jerrymildred

    jerrymildred Senior Member

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    Also, at least one of my apps shows the compressor RPM. I've watched it fluctuate as the demand changed.
     
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  3. kevinwhite

    kevinwhite Active Member

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    Are you sure you are not hearing the engine or engine fan?

    They will cycle even if the A/C is not using much power although the time between engine starts will increase at lower power as the hybrid battery will not discharge so quickly.

    kevin
     
  4. ChapmanF

    ChapmanF Senior Member

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    The compressor will on-off cycle, if the total cooling load is below the compressor's lowest steady-running power setting.
     
  5. fuzzy1

    fuzzy1 Senior Member

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    Perhaps you are thinking of old era AC systems, back when none of the EPA tests were performed with AC on? Prius moved beyond that long ago. Maybe most others have too, now that inefficient AC systems will pull down on EPA fuel economy ratings.
     
  6. DonB CV

    DonB CV Junior Member

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    I have a 'B' mode question. I'm relatively new to Prius but this is my second plug--in... I'm in Southern California where we do have mountains and found B mode better than D/braking for controlling speed on long downhill stretches on back roads. But I'm not clear on how to get out of 'B' when I reach a flat (or uphill) stretch -- no one seems to mention that. Moving the lever up put me in N even though I was going about 45mph. I went back to 'D' with no problem, but that seems odd.
     
  7. jerrymildred

    jerrymildred Senior Member

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    That's what you do. When you want to go back to "D," just put it in "D." The car doesn't care if it's in Park, Reverse, or Braking; it shifts to Drive the same way. :)

    Edit to add: of course you don't want to be going very fast in reverse when you put it in Drive. Safer to stop when switching directions although there are safeties built in. :D
     
    #27 jerrymildred, Apr 4, 2021
    Last edited: Apr 4, 2021
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  8. priusmatty

    priusmatty Active Member

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    Keep it in Eco mode if you want to save fuel, and try to use battery-only cruising as much as possible. Welcome, and enjoy!!
     
  9. ChapmanF

    ChapmanF Senior Member

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    If it's a vanilla Gen 4, not a Prime, getting too fond of battery-only cruising will cost you efficiency. The energy to move the car comes from the gasoline engine; to use it for battery-only cruising, the car has to first put it into the battery, then take it back out, paying conversion losses both ways.

    How to "properly" drive a Prius may have a few fine details to geek about, but an answer that is very close to optimal is to start the car, shift to D, point it where you're going, and press the go pedal.
     
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  10. rjacobs

    rjacobs New Member

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    Weve only had our Gen 4 prius for a week or so and put about 250 miles on it... so far the on board computer says I am averaging 60.1... im not doing anything fancy and not even driving slow(if you dont drive 75 on the highway here in Dallas you will get run down). Just driving normally and using the cruise control on the highway.

    I dont see how some of the techniques like "pulse and glide" can actually be accomplished unless you are completely alone on a flat road...which IMO rarely happens in real life.
     
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  11. fuzzy1

    fuzzy1 Senior Member

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    A form of it can be integrated into stop-and-go city traffic, at least if you are not forced into drag racing between stoplights.

    On rural highways, a form of it can also by synchronized to rolling hills. In my stick shift vehicles, this works at just about any speed. In a Prius, this works best at speeds below the ICE auto-off speed threshold, which is just 46 mph in my Gen3, but is above 60 in a Gen4 Liftback, and above 80 in a Prime. Out here, 60 is considered highway speed, and there is no public facility where 80 isn't ticketable speeding.

    My samplings of Texas traffic, solely as a passenger, are too sparse and old to know what is generally tolerable there. Though it was clear that the few Texas drivers I witnessed were generally not suited to icy conditions, and didn't believe in yielding to pedestrians in crosswalks. And that seems to apply to Texas-plated vehicles visiting here too.
     
    #31 fuzzy1, Apr 5, 2021
    Last edited: Apr 5, 2021
  12. RRxing

    RRxing Senior Member

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    For best economy, drive it as though there is an egg between your foot and the gas or brake pedal. Or, as mentioned earlier, just drive it like any other car- the car will take care of itself.
     
  13. Ramo_958

    Ramo_958 Junior Member

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  14. fuzzy1

    fuzzy1 Senior Member

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    Is there any usefulness to this? In this situation, absent a significant descent, it doesn't act like a downshift of a traditional transmission.
     
  15. Ramo_958

    Ramo_958 Junior Member

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    Car doesn't slide from braking.

    Posted via the PriusChat mobile app.
     
  16. Ramo_958

    Ramo_958 Junior Member

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  17. ChapmanF

    ChapmanF Senior Member

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    I find B mode to generally make the 'braking' effect more pronounced when foot lifted from go pedal; in that respect it is built to feel like a conventional car that's been downshifted. It's kind of a funny combination; B acts like a downshift, in the sense of slowing more aggressively when the go pedal is released, but also sends less of the recovered power to the battery, to be more gentle with it for a long descent.

    If the traction conditions pose a risk of losing grip in D, the risk will be higher in B, at moments when lifting off the go pedal, because of that more aggressive 'braking' feel.

    In my pre-Prius vehicles, I was likely to do the opposite in slick stuff, upshift ... move off from a stop in 2nd rather than 1st, and so on. Keeps the torque to the wheels down, less chance of breaking grip.
     
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  18. fuzzy1

    fuzzy1 Senior Member

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    For a given amount of total braking force, the 2-front-wheels-only of B-mode is far more likely to slide than the equivalent all-4-wheel braking of the foot pedal, because the latter applies about half as much braking force per wheel. And in slippery conditions front-only braking is less directionally stable than all-wheel, even without ABS and VSC engaging.

    The only thing I can see going for B-mode on flat ground is for drivers lacking foot dexterity to evenly control very light braking. Experienced winter drivers should have this well built in.

    I still use B-mode to control speed on winter descents where D-mode would roll faster than I desire.

    Beyond that, I have to agree with Chap, including numerous times needing to start up in higher gear in the old vehicles -- 2nd (very rarely 3rd) in manual transmissions, and a mid-level downshift in an automatic transmission (i.e. not D, but not 1 either).
     
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  19. jerrymildred

    jerrymildred Senior Member

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    So two-wheel braking gives better braking traction than four-wheel braking? Too bad we can't brake with just one wheel when it's slippery.
     
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  20. ChapmanF

    ChapmanF Senior Member

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    Careful what you wish for. This video (recently posted by by Team_Geek in another thread) shows an early car with one-wheel drive.

     
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