Window Tints Put Value, Law in Shade

Question: I have been noticing recently that a lot of cars have tinted windows. I like the way they look, but I am wondering about how well they hold up. Some of the window films look terrible, as if they had formed bubbles or cracks. What are the advantages and disadvantages of window films?--T.I.

Answer: Window tinting is growing in popularity, but it is something that consumers must exercise great caution in purchasing. You hit a bull’s-eye when you raised concerns about the longevity of the product. In addition, there are other important considerations in the quality and legality of window films.

Manufacturers of window films make the claim that they cut glare and reduce solar heating by at least 35% and as much as 65%. With less heat shining into the car, the load on the air conditioner during summer is reduced; supposedly that will save gas.

Another key advantage to window tinting is that it filters out damaging ultraviolet light, which can crack plastic dashboards and rot upholstery fabrics. Plastic and cloth interiors are attacked by ultraviolet light and atmospheric pollutants, but it is the ultraviolet light that does the most damage.

The problem is that in many states, including California, it is illegal to tint either the windshield or the front side windows of cars. In fact, the California Highway Patrol recently issued a letter to window tint installers, warning them that such applications are illegal.

The letter asserted that tinted windows “dangerously reduce a driver’s ability to see after dark” and that they increase the possibility of accidents by eliminating eye contact between drivers.

Martin Processing, a major manufacturer of the window tinting films, launched an attack on the letter, calling it “misleading and ill-informed.” It cited a scientific study that reported tinted windows improve driver response times under glaring sunlight conditions.

Motorists should be reluctant to violate state laws forbidding the use of the tints on front side windows and windshields, because many police agencies will issue tickets. In fact, a General Motors public relations representative told me recently that he was pulled over by the police while driving a promotional Pontiac that had illegally tinted windows used for a GM ad.

In addition, federal laws forbid the selling of cars with extremely dark tinting, commonly known as limousine tints, which permits as little as 5% of light to pass through, on any window.

But federal agencies have not enforced those restrictions in the after-market.

Aside from the safety issue, window tint films have major disadvantages over the long haul. Although they may look good when new, they tend to age quickly.

Even the highest-quality window films, which are available only through professional installation shops, will last only several years.

Then, they begin to form cracks and fade to a sick purple color. These higher-quality films cost anywhere from $125 to $300 to install.

The cheaper films sold in auto parts stores for home application don’t hold up as well, partly because the adhesives are designed to be easier to apply and thus not as strong. They will purple much sooner, especially in sunny areas.

When it comes time to strip out the old window tint film, it is an additional cost of anywhere from $50 to $100. Frequently, the defroster strip on the rear windshield is destroyed, and these strips can be quite costly to replace.

If you are intent on getting your windows tinted, look for a shop that has been in business for a long time. You should seek a major national brand. There are many types and grades of film, such as the Llumar line, produced by Martin. Not all are warranted by the manufacturer.

The question of whether the benefit of window tinting is worth the cost is difficult to answer. It is hard to imagine that window tinting could ever reduce air conditioner loads and thereby reduce fuel consumption enough to offset an investment of several hundred dollars.

But the benefit of preserving interiors with window tinting seems more valid. To some extent, regular window glass in cars filters out some of the ultraviolet light. But getting technical information from manufacturers about how much light is filtered in different car models is like pulling teeth. They usually don’t know and don’t care.

If window tints eliminate interior rot and help keep the car cooler, then they might well be worth several hundred dollars over the life of a car. Another solution would be for the automobile manufacturers to wake up to consumer needs and develop plastics and fabrics resistant to rot in the first place.

Vartabedian cannot answer mail personally but will respond in this column to automotive questions of general interest. Do not telephone. Write to Your Wheels, You section, The Times, Times Mirror Square, Los Angeles 90053.