We developed a windshield washer system that enhances washing performance while maintaining low consumption of windshield washer fluid. The system reduces user stress by shortening the amount of time required to remove dirt and maintaining visibility through the windshield. We analyzed the mechanism through which the windshield wiper and windshield washer remove dirt from the glass surface to improve cleaning efficiency. The mechanism consists of a sequence in which the windshield washer fluid splashes down on the glass surface and lifts dirt which is then wiped away by the windshield wiper blade. We defined the amount of windshield washer fluid needed and the time from splashdown to wiping required to lift dirt and wipe it away with the wiper. Based on this mechanism, we developed a wiper arm with built-in washer nozzles. This wiper arm was equipped on a vehicle and cleaning efficiency was improved by controlling spray amount and spray timing in response to driving conditions and surrounding temperature. This system has achieved a reduction in user stress as well as a 50% reduction in washer fluid consumption.