It’s a Saturday afternoon in the summer and, between the layer of pollen on the hood and the grime on the fenders, your car needs a good wash. Just as you grab your keys to head to the carwash, it starts to rain, and suddenly, you have a free afternoon ahead! The rain will clean the car just fine, right?

Sadly, no. While many people think that a good rainshower is a great substitute for a car wash, that’s not the case. Not only does rain not clean your car well enough to protect it from the hazards of road dirt and chemicals, it also doesn’t even hit all the parts of your car, and it has the potential to cause more harm than good.

Lingering Dirt and Grime

You know how when you’re washing dishes, you always try to spray all the food and residue off each plate? Even when the sink sprayer is on full blast, there are some stubborn bits that you just have to get with a cloth or sponge. 

Expecting rain to clean your car is just the same, only the rain isn’t nearly as effective on your car as your sink sprayer is on a plate. While a heavy shower might remove a light layer of dust, it does nothing against the real dirt, chemicals, and residue that can cause damage to your vehicle. You need vehicle-approved soap, not to mention cleaning tools and a lot more water pressure, to get it clean enough to count.

It’s What’s Underneath

The undercarriage is arguably the part of a vehicle that gets the dirtiest. After all, it’s the closest part to the road. Most people don’t worry about the dirt on the undercarriage because they can’t see it, but it’s every bit as essential to clean as the rest of the vehicle. Water, dirt, and corrosive road chemicals mix together on the undercarriage, causing deterioration and creating mud that fills in essential drainage and ventilation holes. Left unchecked, this can cause significant damage not only to the look of the vehicle, but to its functionality, too. Unfortunately, a rain shower won’t touch the undercarriage — only special, high-powered water jets found in car washes can get it truly clean.

All Water Isn’t Equal

One of the reasons it’s so important to clean your vehicle often is to protect it from the harmful effects of precipitation including snow, sleet, and rain — the same rain you shouldn’t count on to wash your car. That’s because precipitation carries pollutants from the air with it when it falls. 

These pollutants can damage the paint on your car as well as other surfaces on the vehicle. When the water evaporates, the pollutants are left behind and can begin wreaking havoc again next time they get wet. Car washes use water that has gone through a specially designed filtration system, as well as soaps to help remove chemical buildup. 

Rather than relying on rain to wash your car, you should consider protecting it from all precipitation with high-quality automotive wax.