A University of Hanover project dubbed "RainCars" placed cars with different wiper systems under a rain machine in a laboratory under an irrigation system with adjustable nozzles to simulate light to heavy rain.
The researchers said they wanted to find out exactly how wiper speed relates to rainfall intensity.
People seated in the cars adjusted the wiper speed manually, depending on the windscreen visibility.
"The experiments have shown that the front visibility is a good indicator for rainfall intensity," study lead author Ehsan Rabiei said.
Rainfall can vary widely across a region, and while conventional rain gauges are accurate, they are often distributed too sparsely to capture much of this variation, the researchers said.
"If moving cars could be used to measure rainfall the network density could be improved dramatically," project leader Uwe Haberlandt said.
Having good information about precipitation could be helpful in flood prediction and prevention, the researchers said.
The study was published in the journal of the European Geosciences Union.