I just put new wipers on my car this past fall and they are starting to streak. Is there a defect in them? There is probably nothing wrong with your wipers other than being worn out! Most manufacturers recommend replacing wiper blades every six months to a year. This time frame varies because of different types of environments having major effects on the life span of the blades. In northern climates, accumulations of ice and snow damage the structure and rubber that makes up the blade. Conversely, extreme heat can also increase the deterioration of the blades. You can help extend the life by making sure the blade itself is clean and also the use of a windshield treatment like Rain-x to keep the glass free of grit and dirt will help.