Margaret Dunning of Plymouth, Mich., is 101 and her Packard 740 roadster is 81.

PLYMOUTH, Mich.

“I hit it, and it didn’t move,” Ms. Dunning, who turned 101 last month, said.

“That car had a mind of its own,” she said. “And I’m not a very tall person, so I had trouble getting onto the brakes with enough power to hold that engine down. It just got away from me.”

Soon enough, though, she was back at it, rumbling around the back roads of Redford Township, just west of Detroit, where her family owned a sprawling dairy and potato farm. By then she had already been driving for two years.

Before the barn incident, Ms. Dunning’s father had often let his young daughter steer while he operated the other controls. One day he let her do it all, but not without a stern lecture.

“Do you know what you’re controlling here?” she recalled him asking. “Do you know the power that you’re controlling?”

“He explained to me how, for some jobs, it was better to use multiple horses,” she said. “But the minute you lose control, you’ve got wild horses to deal with.

“And that’s how he taught me about horsepower,” Ms. Dunning added. “And it stuck with me.”

After that, Ms. Dunning, an only child, drove everything on the farm that was drivable, she said, including a Maxwell truck and eventually, tractors.

When she was 12 her father died, and his Model T Ford became hers.

Once her politically connected mother, who had arthritic feet and could not drive cars, finagled a driver’s license for the 12-year-old Margaret, she drove her mother everywhere. Her mother drove the farm’s four teams of horses.

“If you had just a little knowledge and some baling wire and bob pins, you could keep the thing going,” she said of the Model T. “It was the little car that made America.”

She cherished her time in the car alone, reaching into the wind for roadside stalks of fragrant sweet clover. “I’d see a few friends or race past a blind pig,” she said, using the euphemism for Prohibition-era drinking establishments. “Before I could get home, people would be calling saying, ‘I think I just saw Margaret, with quite a dust pile behind her.’ ”

In those days there was something else in the air: the excitement spawned by a burgeoning auto industry. Henry Ford not only led that wave, but to the Dunnings he was a friend and neighbor who lived minutes away.

“Dad would come in and say, ‘Well, Henry’s outside and I’ve asked him to stay for dinner,’ ” she said. “Mom had made huckleberry pie and offered Henry some.

“He said that was his favorite pie — I think he was being polite, but he was marvelous just like that.”

She added, “He always wore a hat with a sizable brim and a black band, and he’d push it off his face when he talked to you, and looked you right in the eye.”

Ms. Dunning, who never married, attended a private high school in Wellesley, Mass., before enrolling at the University of Michigan, intending to study business.

“When I was little, Mom asked me what I thought I wanted to do for a living,” she said. “I told her ‘to buy and sell.’ I think that surprised her.”

She dropped out of college during the Depression to help at her mother’s real estate business and later had successful turns in banking and retail.

All along she supported her beloved town of Plymouth, where she has lived in the same home since she was 13. In the 1940s she and her mother donated property to establish what is now the Dunning-Hough Library. She has also donated more than $1 million to the Plymouth Historical Museum.

Her love affair with vehicles never waned. She drove a truck as a Red Cross volunteer and has owned a parade of classic and antique cars. At her home, she also keeps a 1931 Ford Model A, a 1966 Cadillac DeVille that she often drives to car meets, a 1975 Cadillac Eldorado convertible and her everyday car, a 2003 DeVille. A battered Model T steering wheel is her garage doorstop.

But her real love is a cream-color 1930 Packard 740 roadster, which she has owned since 1949. She plans to show the Packard at the Concours d’Élégance of America in Plymouth on July 31 .