Keeping your windshield clean — tips and tricks to fuel safety

Keeping your windshield clean isn’t just about the vehicle looking good. Visibility is essential to safety, which means wiper blades need to be in top condition and a driver’s windshield washer fluid bottle should be full.

“If people replace their wiper blades every six to nine months, they will enjoy better visibility,” says Ron Fausnight, group technical manager of chemicals and appearance products for ITW Global Brands, which markets Rain-X.

“Wiper blades will deteriorate from use, especially if there’s a lot of gritty material on the glass.”

Guck can form on the windshield even on dry, sunny days. Insects and bird droppings are the most noticeable culprits, but it can also include sticky substances kicked up off the asphalt by other vehicles: dust and grime, oil, and even the thin film of rubber that builds up on the road from the thousands of tires driving over it.

If the windshield is dry, it should always be moistened with the washers before the wipers are turned on. Not only is that grime hard on the rubber, but it can potentially scratch the glass.

When you wash your car, it’s common for minerals in the water to dry on the windshield, causing spots. It can be difficult to remove these dried-on deposits and a glass cleaner may need to be used to remove them.

Spray-on or wipe-on water repellents leave a thin film of silicon on the glass that causes the water to bead up and flow away, instead of drying up and leaving the minerals behind.

Windshield wipers are actually squeegees, and while they look like thin blades, a peek under magnification reveals their edges are square. One corner of this square edge drags across the glass when the wipers move in one direction, and then the blade is flipped and the other corner does the job when the wiper goes the other way. This constant push-pull motion does an excellent job of keeping the windshield clear when it’s raining, but it’s also why the blades eventually wear out.

All types of washer fluid will clean a windshield, but summer-specific ones do a better job of removing bugs and grime, while winter fluid is less likely to freeze.

Plain water shouldn’t be used to clean a windshield, since it doesn’t clean as well and can damage the motor if there’s any left in the system when cold weather returns.

When to replace wipers

Streaks mean replacement

Wiper blades should be replaced any time they start to leave streaks on the windshield, if the rubber starts to tear, or if they continually “chatter” when wiping on wet glass.

Because the rear window on an SUV or hatchback gets so grimy, this wiper can wear fairly quickly. Replace it promptly to avoid scratching the glass.

Many vehicles have two different sized front blades, depending on the windshield size and shape, to do the best job of cleaning.

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