Even with a very high pressure washer you can always select wider tips that spread the water and reduce the force on the truck. And you can keep the tip farther away from the truck, which also reduces the force. I've used mine several times, but I put a 40 degree tip on it and keep it about 10" away from the vehicles. It's a 2700psi washer, and with a 15-20 degree tip it peels paint off wood at 4".