It’s fairly common to be told that you shouldn’t clean your car with a pressure washer as it will damage the paintwork. The theory is that the pressurized water drives the dirt particles into and along the surface of your paintwork causing scratches. The alternative would be to use a hosepipe but even this still requires some pressure to effectively remove dirt & contaminants.
A hosepipe does not have the level of pressure that a machine does but it does have a greater volume and weight of water. So if a pressure washer damaged your paintwork then surely using a semi pressurized hosepipe would also be capable of inflicting similar damage?
The truth is that the only way you could damage the paintwork of your car with a pressure washer would be if you were to use a massively powerful machine and hold it too close to the surface which would result in the paintwork actually being stripped off the vehicle.
When using a pressure washer to clean a car the water does not actually drive the dirt particles into the surface of the paintwork, it lifts and encapsulates them by getting in behind them, therefore effectively creating a protective layer of water between the dirt particles and the paintwork. Add to this the fact that if you sufficiently pre foam your car with a suitable product before rinsing (which you should do) the dirt particles will already have been effectively loosened and lifted from the surface by the foam before you even come to rinse it down with a pressure washer.
It is completely safe to use a pressure washer to clean your car as long as the machine you are using is suitable and not excessively powerful, and that you ensure you do not hold the jet of water too close to the paintwork, or drive water into sensitive areas such as window seals or corroded bodywork. It is other areas of the car cleaning process that can cause damage to your paintwork and it is here where more attention should be payed.
