Daytime running lights are sufficient

Question: I have recently encountered a number of stretches of the roadway that require drivers to turn on their headlights during the daytime. Can you tell me whether running lights that are now equipped on many late-model cars satisfy this requirement?

-- D.D.

Answer: The California Highway Patrol’s official position on this matter is that daytime running lights satisfy that requirement, spokesman Steve Kohler said.

The common-sense rules of the road also would suggest that daytime running lights would provide the visibility that highway engineers expected when they posted the legal requirements for headlights.

On the other hand, I could not find where the motor vehicle code specifically says daytime running lights meet the legal requirement for daytime headlights. The running lights are not quite as bright as regular headlights. Nonetheless, I would take the CHP at its word.

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Q: A quick-lube shop just recommended that I flush my engine, a service that costs more than I can afford. Is this necessary? I was told it would help keep my engine sludge-free.

-- D.W.

A: Flushing has little demonstrable benefit for an engine that is properly maintained. If you change your oil regularly at intervals of 3,000 or even 4,000 miles, you already are keeping it much cleaner than the manufacturer had anticipated.

But many car owners don’t bother to keep track of when they change their oil. They accumulate thousands of miles over the maximum recommended interval. Even in most of these cases, the engines continue to perform reasonably well.

So you can buy an engine flush if you think you have abused your engine or if it is an engine model with noted sludge issues, such as some Toyota models that have been granted extended warranties.

On average, flushes and special cleanings are not going to give much benefit. If you want to spend some extra money, have the oil, engine coolant and transmission fluid changed more frequently than recommended in the owner’s manual. You also might consider having the hydraulic lines in the braking system bled every several years to help prevent caliper damage.

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Q: I assume that all automobile companies have the option to locate the gas tank cap anywhere they want. If that is true, why would anyone put it on the passenger side of the vehicle? For someone with a handicap (like myself), it is a real handicap. I will never again buy an automobile with access on the passenger side.

-- W.G.N.

A: The gas tank filler neck is usually placed by automotive designers on the side that most easily accommodates the placement of the tank. Sometimes, other structural issues limit their choice.

But they could design cars with a standardized neck placement. Over time, filler necks have appeared in almost every conceivable position.

On General Motors pickup trucks in the 1960s, the gas tanks were placed on the side of the vehicle and the filler necks behind the driver’s shoulders, a position that led to lawsuits alleging that it contributed to explosions during broadside accidents.

Historically, many passenger vehicles had filler necks in the rear, under the trunk lids; the fillers were positioned there because the tanks were under the trunks. And Volkswagen Beetles had their filler necks on the left front fender, another hazardous location.

Today, it is universally accepted that the safest place for a gas tank is in front of the rear axle, where it is protected from a variety of potential impacts. But engineers still can place filler necks either on the right or left sides of vehicles.

It’s a problem that causes snarls at gas stations, because drivers need to enter lines in different directions to allow the fuel nozzles to reach. And, obviously, it is confusing to people who rent cars.

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Write to Ralph Vartabedian at Your Wheels, Business Section, Los Angeles Times, 202 W. 1st St., Los Angeles, CA 90012;

e-mail: ralph.vartabedian@latimes.com.