Your SUV isn't monsoon-proof. Here's how to protect from water damage

The Print

01-06-2025

You might think that just because you have a high-riding SUV, you are secure from water. Well, the weird thing is that most cars, including SUVs, have their air intake under the grille. This means that despite filters to protect the intakes from excessive water, in extreme conditions, water will get into the engine. Going through a few puddles or a small patch of standing water is fine, but a simple rule of thumb is that if water reaches the door sill, it is best to avoid going forward. Water can also flood the exhaust system, so when driving over waterlogged patches, it is advisable to keep pressure on the throttle.
Now, while I can't stop you from doing something stupid, I can at least warn you about a couple of things. First off, there is something called a hydrostatic lock. Simply put, unlike air, water does not compress under the pressure of a piston. A small splash won't do much harm to the engine, but when you wade through deep water, a lot of it can sucked in through the air intake. Thus, the fuel-air mixture in your engine suddenly has a lot more water than air, and modern engines with advanced sensors switch themselves off before they seize completely. This is particularly true of diesel engines, which use very high-pressure injectors and also depend on a very high compression ratio to ignite the fuel. Many luxury diesel cars actually become expensive barges whenever it rains.
Don't forget to check the rubber bits, starting with the tyres. While driving on wet roads, there is always a risk of aquaplaning. This is when a thin layer of water develops between the road surface and the tyre, causing the car to lose grip completely under heavy acceleration or braking. Additionally, as oil and fuel leaks are common on public roads during rain, these can rise to the surface, making slippery conditions even worse. That's why tyres need a good amount of tread—at least 50-60 mm (a quarter of an inch)— to maintain proper grip. Thankfully, most new cars also have features like Electronic Stability Control (ESC) that help keep the car steady in wet and slippery conditions.
It isn't just the tyres that you need to check—before the monsoon hits, ensure that your wipers are working properly. The blades should be even and not leave streaks on the windscreen. Believe me, when you are caught in heavy rain and your wipers are working full-time, having wiper blades that are dull or a motor that isn't working—even though it is a rare failure—it can leave you nearly blind behind the wheel. And talking of visibility, while it isn't a great idea to drive in the dark in heavy rains, sometimes one has little choice. So, check your headlights too. Some types of headlights tend to reflect a lot on raindrops, particularly on high-beam, so be aware. Water can also refract light, so visibility of oncoming traffic might be hindered, so drive at a sensible speed.
You should also run your fingers through all the seals on your car, especially in wet areas. This includes the door seals. If standing water reaches the sills, it can seep into the cabin. Some off-roaders let you pop open a plug and drain the water out. But on other cars with electric seats and a large number of onboard electronics, water in the cabin could be fatal for the vehicle. By the way, don't forget the sunroof. They are becoming increasingly popular on modern vehicles and there are multiple videos on YouTube where influencers talk about sunroof leaks. Sure, no sunroof is designed to be parked under a waterfall, but it doesn't hurt to check for any obvious damage.
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Monsoon insured
Almost 15 years ago, I had to swerve to avoid a child running across a highway while driving a BMW 3-series and ended up in a flooded ditch. From the outside, you would not have been able to tell that the car had been in an accident. But BMW India later told me that the car was a write-off. Fixing it meant changing the seats, the headlights, and dozens of sensors. The insurance firm found it cheaper to scrap the vehicle and strip it for parts.
Incidentally, this is why you must always add the 'flood' rider on any insurance policy on a modern car. Those eight-way electrically powered, ventilated seats are a cool feature, but if water damage fries them, you're looking at a repair bill exceeding a lakh. This flood rider also covers a hydrostatic lock or other flood-related damage, and this could be in addition to the comprehensive insurance package. Make sure it covers damage to electronics as well, because you could find your car in a flooded basement parking lot for no fault of your own.
Driving in extreme wet conditions should come naturally to most Indians. New features like Electronic Stability Control (ESC) and modern tyres have made things easier, but today's cars with their electronics and sensors have also made things a lot more complicated. So, the best thing to do is to be aware, be insured, and be careful while driving.
@kushanmitra is an automotive journalist based in New Delhi. Views are personal.
(Edited by Ratan Priya)