In a traditional IC car when driving through water such as a flooded road or a ford the recommendation is to keep the revs up by using more throttle than is necessary. This ensures that the exhaust gas flow prevents water entering the exhaust pipe and prevents damage to the catalytic converter and even engine.

In a hybrid car increased throttle does not ensure that the IC engine will be producing lots of exhaust, or even be on. Is there a recommended way to prevent water entering the exhaust pipe in such a car?

Actually this is a theoretical question that occured to me. It was prompted by experiences I was told about relating to a Mitsubishi Outlander PHEV (fairly new, I do not know the year).

  • It would be helpful to know which specific hybrid you are referring to as different vehicles have different modes of operation. Please add vehicle make, model and year to your question. This does also appear to be a question about driving technique. Jan 30, 2020 at 13:41
  • I have added a comment about the vehicle. I agree it is about driving technique, and any appropriate action should be taken on that account.
    – Dave
    Jan 30, 2020 at 13:56
  • Best vehicle for driving in a flood is any that does not have many electrics so old diesel Landrover etc Anything else will have problems - just look at the number of posts on here that start “I drove through a flood...”.
    – Solar Mike
    Jan 30, 2020 at 14:02
  • Air intakes are low at the front on many cars, if it's deep enough to come in the exhaust it may be deep enough to get sucked in the air intake, which is far worse
    – Dave Smith
    Jan 30, 2020 at 16:08
  • Conventional gas vehicles make use of a snorkel air intake. Perhaps you could adapt a lightning rod for something more appropriate to a hybrid.
    – user16128
    Jan 31, 2020 at 8:08

2 Answers 2


I understand most EV cars have the battery on the bottom ; I think there is a problem if the battery is submerged, especially in salt water.


In the case of the Mitsubishi PHEV, I'd suggest in switching the vehicle to Parallel mode which will ensure that the engine is running at all times and then use the same guidance as applies to a combustion / compression engined vehicle.

Of course the preference is to avoid completely driving through any body of water at all.

  • How about plugging the exhaust and using electric only mode?
    – towe
    Jan 30, 2020 at 14:57
  • @towe you cannot fully avoid the combustion to come back on. which would be fatal
    – AnyOneElse
    Jan 30, 2020 at 15:02
  • 1
    I wouldn't suggest plugging a hot exhaust and them submerging it in water. Jan 30, 2020 at 15:11

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