On your car’s windshield, the wiper blades each operate in a smooth semi-circle motion from the wiper arm pivot. The wipers clear the view in front of the driver and front passenger and clear the center of the rear window if equipped with a rear wiper.
There is always a section on the window that doesn’t get cleared by the wiper blades. Specifically, the passenger side top corner, and the driver’s side lower corners aren’t cleared very well. It may be tempting to replace your windshield wipers with longer blades in order to clear more of the glass, but how do you know if that's a good idea?
How to choose the correct wiper blades
Wiper blades are vehicle specific. The passenger and driver’s side wiper blades are the same size on some vehicles, while on others they are vastly different. The best wiper blade sizes for each of your wipers are selected for proper fitment and to clear the most area on the windshield as possible.
If you replace the wiper blades on your car with larger wipers, you will find that one or both will either hang off the side of the windshield or hit the top windshield trim when in the totally vertical position. This can cause extremely premature wear on the wiper blades and spots that don’t get cleared when the wiper blade isn’t flush with the windshield. If the blades are too long, they can also hit each other, tangle up, and possibly damage the wiper blades, arms, and even the wiper motor and transmission.
If you replace your wipers with smaller blades for some reason, you will likely find there are much larger spots that aren’t cleared including critical viewing areas.
Only replace your wiper blades with the size of blades specified by the manufacturer to ensure proper fitment and to prevent damage. You can easily find out the size you need by checking your owner's manual or using an online blade size finder.