Costas Athan
Senior member
Here is some fairly heavy rain, although I have driven through heavier:
http://www.youtube.com/watch?v=WNTTf6dIygA
Skip to 2:00 or so for the goodies. If water isn't sheeting across your windscreen even with the wipers on high, it's not "heavy".
But it is! Watch carefully the bottom of the windshield from 7:30 mark onwards on 1080p and full screen. Wipers are on high. Is that just a sprinkle as many guys say? In my opinion not. And I'm doing no more than 30 mph. I mention this because it is really important. If you are going at 100 mph even a moderate rain can decrease visibility because the wipers don't have the time to remove the water, but if you slow down you'll see the real intensity of the rain.