Never would I utter a word of scorn about a 1993 automobile, since I own one and am trying to keep it alive well into the 21st century.

But the truth is that stuff breaks on seven-year-old cars -- stuff that you never think about until it lets you down.

That, in a proverbial nutshell, is the story of Jen Portuese, of Reston, and her 1993 Nissan Sentra. Like almost every car still on the road, Jen's has a warning light that is supposed to pop on when she's almost out of gas.

But one day this summer, the light was too pooped to pop. Thus did Jen spend a panicky couple of minutes in a dead car on Lawyers Road in Reston -- a panic she could and should have done without.

As Jen describes it, she was tootling toward an appointment with a potential client. As she neared the intersection of Hunter Mill Road, her car began a death rattle.

Jen looked at the gas gauge. It showed her tank as being a quarter full. But just moments later, before she had a chance to pull over, the gauge was hugging E-for-empty and Jen was becalmed in the single northbound lane.

Could a car really blow through a quarter of a tank of gas in no time flat? Jen doubted it. But this was no time for theoretical debates.

Jen went rrr-rrr-rrr, in an effort to restart the car. No success. So she hopped out and tried to wave cars around hers.

Within seconds, a "large white car" containing two men pulled up beside Jen's stricken Nissan, she reports. Being a native New Yorker, Jen is very suspicious of strangers -- "especially if someone is being nice to me."

These guys were more than nice. They were incredible.

One man backed Jen's car onto the shoulder. Then he went to fetch his gas can. Then he returned to the scene, and both men went to buy gas. They were back "quick as a flash," Jen says. They waited until Jen's car started. And they refused to let Jen pay for the gas. She made the meeting with her client only a couple of minutes late.

"The experience renewed my conviction that I made the right decision to move down here from Long Island two years ago," Jen says. "Makes me proud to be a transplanted Virginian!"

But what was up with that crazy gas gauge? And what can you and I do to prevent something similar?

Jay Sponseller, a service expert at Herb Gordon Nissan in Silver Spring, said he could think of three reasons Jen went from plenty of gas to zero in the blink of an eye:

1) The sensor in the gas tank doesn't work.

2) The float in the tank broke (that's how the sensor knows how much gas is in the tank).

3) The sensor is coated by gas or some sort of petroleum-based crud and needs to be repaired or replaced.

Jay said he doesn't think Jen's car suddenly burned two or three gallons of gas. He thinks the gauge was defective. He said the repairs he suggested would cost $75 to $250, depending on how much work was needed.

Jay said the gas warning light on a 1993 Nissan should go on when two or three gallons remain. The tank holds 12 to 15 gallons, depending on the model, he said.

Asked to comment, a manager at a Nissan dealership in Rockville said, "The first thing I would do is climb under the car and see if there's a large dent in the fuel tank." The manager declined to give his name.

Jen will never be in a no-gas way again. Her boyfriend checked out her tank and said there was nothing wrong with it. Meanwhile, Jen says she will never let herself drop below a quarter of a tank because she remains "paranoid about the whole thing."

As for the rest of us who own aging cars, it might not hurt to let the gas tank drift down toward empty, just to see if your warning light comes on when it should.

I wouldn't run this little experiment on the Beltway at rush hour. Do it in a shopping center parking lot, where you can coast safely to a stop if worst comes to worst.

But do it. If you show your Ancientmobile how much you love it, perhaps it won't die for good before, oh, say, 2010.

Always said I could pray with the best of 'em.

Mike Stamler, of Silver Spring, wrote me an e-mail that he said was "worth interrupting my lunch." I suspect it'll be worth reading over your breakfast.

One recent evening rush hour, Mike was waiting for a Red Line train at Metro Center. He spotted "a family, obviously tourists, gazing, eyes glazed over, at the posts that list the Red Line stops."

Mike says he likes to help such obviously befuddled folk "because it's fun." In this case, the family wanted to go to Chinatown. Mike instructed them to hop aboard the next Red Line train and go one stop, to Gallery Place.

The family said thanks. Then the father asked: "Why is everyone around here so nice?"

Washingtonians are nice? Mike says he was so taken aback "that I could muster only, `It must be because it's the evening rush hour. We're probably a lot worse in the morning.' "

The father said that back home in supposedly friendly California, "everyone's grouchy until they get home, and then some."

Two cliches bite the dust in one encounter. Far above average, eh?