Pressure washers are great tools for sprucing up outdoor surfaces such as driveways, decking, and patios in a much easier (and I think more satisfying) way than scrubbing for hours on all-fours (as well as using much less water, very green!).
Is it possible, though, to use a pressure washer to clean your car without damaging the paintwork?
It is generally safe to use a low-to-mid range psi pressure washer to clean your car without damaging the paint. Using a more powerful washer (anything above 2000 psi) can increase the risk of scratching or nicking the paint. There are a variety of nozzles and attachments that can make this easier and allow you to clean your car in no time.
When not to use a pressure washer on your car!
Let’s say some rogue stones had already managed to cause some chips to the paint on your car. If a pressure washer was used here this could simply make this damage worse, as the water would be able to get under the paint and start stripping it off from those nicks. The tried and tested “bucket and sponge” method is your best bet to a shiny car here.
The same goes for if you have spotted any patches of rust on your car. Any opportunity for the water to peel back the clear coat and paint, that water is going to take it.
Another time to avoid the pressure washer is if your car has very old tires. Over time the rubber on tires wears away and becomes thinner. Applying a pressurized jet of water to already worn rubber could end up with a burst tire, so it’s in your best interests to check your tires regularly (but you already knew that).
One slightly more niche situation for any vintage car collectors out there. Older cars may not (most likely) be made to the same specifications as more modern models, and will definitely not have the same kind of clear coat protection that cars these days have. A pressure washer has the potential to cause more damage to older vehicles so if you want to keep your vintage cars pretty, steer clear of the pressure washers.
Now that I’ve covered the pressure washer no-gos, we can look at how you can clean your car effectively using one.
What psi is safe to use for cleaning?
In general, it is best not to exceed about 2000 psi when cleaning your car. Of course, this will vary depending on what kind of spray attachments you may be using, how far from the car you’re standing and which parts of the car you’re cleaning.
You can use higher pressure when using a nozzle that spreads the water more widely, like a fan head. If you are using a thin jet of water, such as from a laser nozzle this could seriously damage your paintwork (not to mention the rest of the car).
It’s best to keep the higher end of your pressure setting for the main body of the car and use a lower psi on more fragile areas like windows, tires, and lights.
The same can be said for areas where there are rubber seals, as a higher pressure of water leads to an increased risk of water getting into your car and ruining the upholstery (we weren’t cleaning the inside until later, check out car vacuums here).
What nozzles are best for cleaning your car?
On most household pressure washers available, there is a wide range of nozzles you could choose to clean your car.
As I’ve written above, you want to try and match the pressure to the nozzle you’re using. So if you’re going for the higher pressure, switch to a nozzle with a wider spray angle (40 degrees is a common fan spray setting that will give you good coverage).
If you’ve got some particularly stubborn grime to get rid of, this spray angle could be reduced to apply higher pressure to these parts, but again, stay away from windows, tires, and lights!
A fan nozzle on a reasonably high-pressure setting can get rid of excess dirt and debris (think of it like vacuuming your floor before mopping).
A broader spray nozzle is great for applying the detergent for the pre-clean and quickly covering your car in suds.
If your pressure washer supports a brush-tipped nozzle, then this is a good option for getting rid of ground-in dirt. If you’re using the same brush to do the wheels or wheel arches then do these bits last to avoid bringing any dirt caked onto them to the rest of the car.
A broad but relatively high-pressure nozzle is then best for the final rinse of the car. All the dirt you’ve managed to lift will come sliding right off. Always start from the top of the car and work down (gravity works wonders).
No matter which nozzle you end up using, it’s always best to stay about 4 feet from where you’re cleaning. This reduces the impact of the water, reducing the risk of damage, and also stops you from damaging the paint with the nozzle itself!
That being said, if you happen to use a pressure washer with no attachable nozzles, it is possible to tune the pressure yourself by simply standing further away from or closer to the car.
General tips when cleaning your car with a pressure washer
There is a lot of different advice on the general best practices when using a pressure washer, most of which can apply here as well. Here’s a list of the most common points:
- Always check your car over before doing any sort of cleaning for chips or rust patches in the paint, as washing with these will only make it worse
- Try to avoid cleaning your car on a surface with loose stone chippings. That jet of water may not damage your paint but a flying stone will definitely leave a mark!
- As with any pressure washing situation, wear something that covers your feet
- Apply the water to the car at about a 45-degree angle so that any dirt is being ejected off the surface rather than driven further into the paint
- Regularly rinse brush attachments (if you’re using them) so that they don’t drag grit/dirt to other parts of the car
- If you have a washer that can be used to spray detergent, always dilute it, otherwise, you may be left with blemishes on your paintwork
- Avoid nozzles labeled “rotary cleaners”. These are generally way too powerful for car cleaning and can definitely damage that paint job
- Always keep the pressure washer moving, to avoid concentrating water on any one part. Not only will this give you a more even clean, but the risk of damaging the paint is also lower too
- If in any doubt over how close to spray the washer, always follow the manufacturer’s guidelines
Overall it is perfectly safe to use a pressure washer to clean your car without damaging the paint. There are usually a whole load of different nozzles for home-use pressure washers that can make the job easier and, let’s face it, using a pressure washer is a lot more fun.
As long as you don’t go too crazy with the pressure and keep the higher pressure away from those fragile parts, you’ll be able to clean your car in no time without any issues.