First off, don’t do this. Second, really don’t do it. Not only could you damage your car, but any time you drive a car into more than 4 or 5 inches of water you are taking a big chance, especially with moving water or when you have no clue as to why the water is rising.
OK, so common sense aside, this Tesla S driver successfully navigated through a flooded tunnel in Russia, according to Electrek. As the website points out, some people get skittish about electricity and water and how that might apply to electric cars. And certainly the two don’t mix well. That’s why we don’t have electric outlets near bathtubs, but it’s not quite the same with cars.
The Tesla’s sealed battery and electric motor are actually less vulnerable to damage from being submerged in water than internal combustion engines. Those vertical pipes that Jeeps or Land Rovers have extending up on one side of the vehicle near the windshield are called snorkels, and they serve the same purpose as the more familiar marine snorkels. With an engine snorkel, those rough and ready SUVs can drive through water without the engines choking on the lack of oxygen. (Not that many vehicles so equipped actually use the feature, but hey, it looks the part.)
Just like people, internal combustion engines need an air intake, but electric cars don’t. So that’s why when you watch the video the Tesla driver keeps moving while the other, presumably gasoline or diesel-powered cars, stall. It’s a nice touch that when the Tesla driver gets all the way through the tunnel and up out of the water, he or she weaves side to side like a puppy shaking off water after a bath.
So it looks like this driver made it out of the flooded tunnel just fine. As Electrek pointed out, however, if there was any damage from flooding the Tesla warranty wouldn’t cover it, as with all car manufacturers.