Question: What is the benefit of tinted...

Question: What is the benefit of tinted windows? Are they legal? With all the freeway shootings, lane switching and tail gating, I like to see hostile drivers.

H.H.G.

Answer: Auto manufacturers have substantially increased the size of car windows in recent years, for both cosmetic and safety reasons. One result has been a substantial increase in solar heating inside cars, and tint films are one response.

Tint films have become cosmetic vogue, although there are plenty of real benefits and disadvantages. I doubt that they have contributed to any freeway shootings, although my imagination runs wild when I think about what goes on behind those dark windows.

Window films producers claim that they eliminate sunlight glare, reduce interior heat, increase privacy and improve safety by helping prevent glass from shattering in collisions.

The films, which consist of a coated or dyed polyester, are supposed to reduce solar heating inside a closed car by a third to two-thirds. That decreases the load on the air-conditioning system, improves fuel economy and keeps occupants cooler.

But the cooling effect depends on how many windows are treated. In California, and in many other states, it is illegal to apply tint films to the front windshield and front passenger windows, cutting in half the surface area that can be tinted.

The laws permit tinting of rear side and rear windows with films that meet certain light-transmission standards. Rear window tinting can be a major benefit in such vehicles as station wagons.

The window film industry claims that its products reduce glare and improve driver vision. Obviously, windshield glare is the biggest problem for motorists, and windshields can not legally be covered.

Finally, the film can significantly help reduce wear on upholstery, which is ravaged by heat and ultraviolet light. Most films filter 99% of ultraviolet light, although some car glass filters out substantial light as well.

The cost to tint windows varies widely. If you apply the material yourself, it could cost as little as $25. A professional job can cost several hundred dollars.

The quality of the material and installation will determine how long the film holds up. Eventually, films can turn purple and form blisters. The better films are sold to professionals only, although a competent home application can last several years.

Q: In Newport Beach, we are having a 30% cutback in our water allocation. I haven’t washed my Subaru in three months, thanks to a product called Kozak, which gets dirt off without any water.--B. R.

A: After a recent Wheels column about keeping cars clean without water, I was inundated with letters from readers about Kozak Auto Drywash Cloths, which sounds like something concocted just for the California drought.

In fact, they have been made in Batavia, N.Y., since the 1920s. The cotton cloth is woven with a deep nap and treated with a light oil, intended to trap and lift off dirt.

I was skeptical that any cloth could safety lift off dry dirt from a car without scratching the surface. But Paul Harding, a vice president at the firm, said the cloths are widely used by museums and collectors who would never consider dousing their cars with water.

After sampling a Kozak cloth, I can report that it did lift off light dirt but was not very effective at removing dissolved dirt or bird droppings. But the company never claimed the cloths could remove ground-in dirt. I also did not detect any scratches on my finish. The cloths, which cost $8.95, can be ordered by calling (800) 283-WASH.

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