Quote: Tgo When we upsize, we are reducing the pressure with which the edge sits against the windshield. Which should result in longer life. Keeping apples to apples comparison (same style of blade), the only reasons I could come up with for upsizing was the Increased sweep coverage. Is it that important than getting a clean sweep?So, why do we & why should we, still upsize the wipers?I think your analysis is correct. Increasing the wiper blade size will decrease the pressure (Force per unit length in this case of linear contact) and that will reduce the wiping performance, but gain increased sweep area. However, increased sweep area is very tricky, because modern cars have complex windshield shapes, and trying to increase the sweep area may result into interference between the two blades (I have seen this happening on a few cars), and/or the blades touching the outer edge of the windshield and making hitting sounds (I have seen this happening on a few cars too).