Driving through flooded street: EV or Gas mode?

Discussion in 'Gen 3 Prius Technical Discussion' started by Terrell, Aug 22, 2018.

  1. Terrell

    Terrell Member

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    OK, I know, never drive through a flooded street, because 1) you don't know how deep the water is, and 2) you don't know whether the roadway under the water is still there, it may have been washed away. Turn around, don't drown.

    Now that that's said, there's been much flooding around the US, and recently, also here in Wisconsin.

    Cars that plow into water on streets usually die, because of water entering the air intake of the engine, I believe. Then you're stuck. (Which is why it's really stupid to try to go through water fast - it doesn't split the water like Moses, it floods the engine faster!)

    Now my question: What about switching to EV mode (electric only). Now you're using only the electric engine. Would you be able to go through deeper water in EV mode than in normal mode with the gasoline engine? (Assuming you don't lose contact with the road by floating, or get swept away by the current.)

    And yes, I realize driving through deep water ruins the whole car. But let's just ask the question: Gas or Electric? Which will get you further in a flood? Will everything short out? Or keep you going? (No, don't try this!)
     
  2. Maarten28

    Maarten28 Active Member

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    I guess it will make some difference as there will not be any air (and water) sucked into the airfilter, but still, if the water gets as high as your airfilter (but then you're really nice person-deep in water ;) ) it will be likely to seep into the engine. The airfilter itself is a bit of a block of course, no idea how much it will hold off water.
     
  3. worrachai

    worrachai Junior Member

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    In my country(Thailand). Many time was flooded on the main road. 1 time, I drove on the flood high 12" from the floor but continue running with normal mode. It's OK no everything happen.

    By the way, most of driver knew that running on the flood road should not use the air-conditioner.
     
  4. bisco

    bisco cookie crumbler

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    if the water is high enough to reach the air intake, the battery likely will have exploded by then.

    my answer: it won't matter.
     
  5. Grit

    Grit Senior Member

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    The battery internal packs are wired by the pairs, it won't explode. Imagine a flashlight with a lot of D batteries wired in series (lined up) like a 1000 of them. If water gets in, each battery will ground itself and not even explode let alone put out a charge.
     
  6. Terrell

    Terrell Member

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    That might be the case with lithium batteries, but the 2010 uses NiMH batteries, so I doubt that it would explode. Maybe short out, though.
     
  7. Tideland Prius

    Tideland Prius Moderator of the North
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    Well if it's high enough to reach the engine air intake, it's too deep lol.

    The exhaust pipe would be what I'm worried about so if I were in that situation, I would be running in hybrid mode in "B" to keep the gas engine running and reduce the amount of water entering via the exhaust pipe (and potentially damaging the catalytic converter).
     
  8. Terrell

    Terrell Member

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    Wouldn't forward motion keep most water out of the exhaust pipe? If the water is deeper than the pipe, and you're standing still, it will get in. But some water (vapor) gets into the catalytic converter from the engine running normally, and it's the heat that keeps it from pooling up in there, right? Water in the exhaust system is what causes it to eventually rust out. So I wouldn't think getting water in the exhaust pipe would ruin the catalytic converter, but maybe I'm wrong.
     
    #8 Terrell, Aug 28, 2018
    Last edited: Aug 28, 2018
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  9. fuzzy1

    fuzzy1 Senior Member

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    Water condensation in exhaust ought to be much cleaner (from the catalyst perspective, at least) than floodwater.
     
  10. Terrell

    Terrell Member

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    Doesn't the water come into the car, ruining the carpets? And what keeps the car from floating if the water is 12" deep?

    True, floodwater is not at all clean. There were kids playing in the flooded streets and people riding bikes into the water, without realizing the floodwater was contaminated by sewage (the sewers were backing up).
     
  11. Tideland Prius

    Tideland Prius Moderator of the North
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    Depends how deep the water is. You have to be extremely careful and keep that constant speed (as you know, because you were talking about the wave ahead of the car).
     
  12. fuzzy1

    fuzzy1 Senior Member

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    The sewage component should be quite thin, very dilute, negligible to the catalyst. But the mud component can be quite heavy.
     
  13. Terrell

    Terrell Member

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    I drove very slowly through some water that was perhaps to the bottom of the doors after watching other cars go through, so I knew the pavement was still there. I drove very slowly, so water would not splash up into the engine. I drove around three cars ahead of me that had their emergency flashers on and were stopped. I don't know why, perhaps they tried to speed through the water. There were other times when I turned around and tried other ways to get home. One car ahead of me plowed into water halfway up his doors, and there he sat. Or, there he bobbed - for a while. We had some flash flooding Aug 20.
     
  14. bisco

    bisco cookie crumbler

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    maybe start with toyota's thesis on how to repair a flood car, and work backwards from there.
     
  15. Tideland Prius

    Tideland Prius Moderator of the North
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    In your case, either mode is fine but you could stay in EV mode if you're worried about the wake from other vehicles accidentally splashing the engine area.
     
  16. working1

    working1 Active Member

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    I got caught up in the Wisconsin rain on the way home Tuesday with my Prius. Interstate was closed so I made a really bad decision and tried taking a country back road. The next hour was an adventure with at least 10 crossings over flooded roads with moving water, blinding rain, high winds, down trees and a tornado warning. I made it out, but, it could have turned out much differently. Had visions of being featured on the weather channel as an example of what not to do.

    However, the Prius had no issues with these crossings with some of them above the door sill. I kept the car moving at a slow speed. Maybe 5 mph. The Bridgestone SERENITY+ tires felt solid with no indication of hydroplaning. I never thought about keeping it in EV mode, but, odds are it was running in EV mode automatically with the slow speed.

    I've drove more than 300 miles since then without an issue. I'm rotating tires/changing oil this weekend and will inspect for any damage. More worried about running over the tree branches than driving through the water.
     
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  17. Terrell

    Terrell Member

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    Wow! Are you in Sauk? I was also driving Tuesday, saw some water on the roads, but no flooding (Madison). Make sure your carpets didn't get wet, they might mold. Yes, running over tree branches, which could be hidden under the water, can be a problem.

    I damaged the front splash panel on a parking curb, and the oil change door fell off when the insulation got wet and became too heavy for the panel (because not all the screws got put back in correctly at my last oil change, and no, I didn't do it, the dealer did.) So I had it dragging under the car while I was driving, had to stop to stuff it back up and the next day had the dealer replace the whole front splash panel. It was not cheap!
     
  18. edthefox5

    edthefox5 Senior Member

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    That’s so stupid.
     
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