BHPian Tgo recently shared this with other fans.

Some of the basic physics applied to windshield wiper blades does not show the promising results of the increasing trend of wiper blade sizes that many of us are thinking.

Take the wiper of any vehicle as an example. The wiper arm has a spring that pulls the wiper arm towards the windshield. The spring is a component that provides a constant force for the wiper arm.

Let us focus on stress. This is the cross section of the edge, equivalent to a point on the edge. source

The wiper components (components with rubber edges) are always under this constant force. Let's call it F. The length of the blade is L. Each point on the edge that is in contact with the windshield has a component of that force, which will be pressure = F/L (consider line contact for simplicity).

Applied to the basic physics of wiper blades. According to common sense, greater pressure helps the edge to push the windshield more firmly, which should equate to better wiping performance.

As we expand the size, we are reducing the pressure on the edge against the windshield. This should cause performance degradation, but a longer lifespan.

Keeping the comparison between apples and apples (same style blades), the only reason I can think of expanding the size is to increase the scan coverage. Is it more important than cleaning? So, why do we need to increase the size of the wiper?

Here are the GTO's views on the matter:

I have always insisted on OEM size. This seems to solve a problem that no one has encountered!

The following are BHPian Dr.AD’s views on the matter:

I think your analysis is correct. Increasing the size of the wiper blade will reduce the pressure (force per unit length in the case of this linear contact), which will reduce the wiper performance, but will increase the swept area. However, increasing the sweep area is very tricky, because the windshield shape of modern cars is complicated, and trying to increase the sweep area may cause interference between the two blades (I have seen this in several cars) , And/or the blades touch the outer edge of the windshield and make a crashing sound (I have seen this in several cars).

There is usually not enough space around the windshield to increase the cleaning area simply by using larger blades without causing any interference. If it is indeed possible, most car manufacturers will use larger blades first.

The wiper design is very complicated, and most OEMs will closely match the shape, size, and maximum possible coverage area of ​​the windshield without any interference. Attempting to mess up usually leads to unnecessary problems that didn't exist in the first place.

The following are BHPian dhanushs' views on the matter:

There is a certain amount of pressure to remove the water on the windshield. Once this point is reached, any more pressure will be meaningless.

The manufacturing of each component in the car has a certain tolerance, which is what we take advantage of when upgrading. Just as we use the torque rating tolerances of the gearbox and drive shaft when remapping, in this case, we use spring stiffness to increase the wipe area.

So if you can use a larger blade to get more wiping area without interfering with other blades or windshield beads, then go for it.

Check out BHPian comments for more insights and information.

Keep yourself up to date with the Indian automotive industry via Twitter, Youtube or RSS feeds.