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Shedding Some Light on the Use of Halogen Headlamps

August 14, 1986|RALPH VARTABEDIAN | Times Staff Writer

Question: I've asked several car salesmen why all the new cars have halogen headlights, and they answer: "They're brighter." This raises another question: Why do we need brighter lights that are five or more times costlier than tungsten lights?--C.J.

Answer: I couldn't agree with you more. Several years ago, the California Highway Patrol evaluated halogen bulbs and found that they were no better than traditional lamps in low-beam usage. Whatever advantage they offered was in high beam, which is seldom used by the majority of motorists.

Another problem with halogen lamps is that they can burn out frequently on some cars. Just to mention my own experience, I went through three sets of halogen headlights in only 30,000 miles on my car. I switched to sealed-beam incandescent lamps and haven't had a burnout in 40,000 miles.

Halogen bulbs have a tungsten filament that is one-half the diameter of regular incandescent bulbs, and they burn at a much higher temperature, which makes them more susceptible to vibration damage and voltage surges. A surge of only 1.5 volts, for example, can shorten their life or cause them to burn out instantaneously.

Produce More Light

Halogen bulbs produce 30% more light per watt of electricity, but most halogen bulbs are rated at about 30% less wattage. So, you are really not getting any more light, but it is a whiter light and a less scattered beam.

And, as you say, they're more expensive. Rectangular halogen headlamps cost $9 at discount auto stores versus $6 for a tungsten. You can jack that up if you go to a dealer's parts counter.

Incidently, they are called halogen lamps because the bulbs contain a small amount of iodine gas, which is a member of the halogen gas family. Thus, they could just as easily be called iodine bulbs, but that probably doesn't have the marketing pizazz of something called halogen.

Q: My husband wanted our new car to have a five-speed transmission, so we got one on our 1986 Toyota Camry. I thought it would pose no problems, because I cut my driving teeth on a four-speed transmission. Not so. Getting out of fifth gear and into fourth is traumatic. I am afraid of thrusting the transmission into reverse or shifting into second instead of fourth. My solution is to ignore fifth gear and cruise in fourth instead. Will this damage the car?--D.B.

A: It's unlikely to damage the engine, but I don't like your solution just the same.

First, it is impossible to shift from fifth gear into reverse, because the transmission has a mechanical lockout to prevent it. You'd need the strength of a gorilla to jam the shift lever through the lockout.

Avoiding the Mistake

Second, a cool head and some simple instruction should help you avoid the mistake of shifting from fifth gear into second, when you intended to shift into fourth.

The biggest mistake you can make is to force the shift lever through the gates. The shift lever is spring-activated to center itself in neutral at the right of the H pattern, under third and over fourth. So, by just shifting to neutral, you should always know which way to pull the lever to get to the gear you want.

You have to learn to guide the shift lever. As you pull it out of fifth gear, it will automatically position itself in neutral over the fourth gear slot. Just pull it straight back into fourth gear.

Although keeping the car in fourth gear to cruise will not rev up the engine enough to cause any damage, it will cause the engine to wear faster than if you cruise in fifth gear. In addition, your fuel economy will suffer.

Ralph 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.

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