While the French famously obsess about the dilution of their culture at home, it is not unfair to say that their great nation’s cultural sway appears to have dwindled in the larger world as well. To give two examples that touch me where I live, the primacy of French cuisine — once regarded as the world’s best — is finis. No longer is the cozy French bistro a staple of every American city.

And though little remarked upon, so, too, can be seen the declining fortune of the French automobile, a device whose invention traces to Nicolas-Joseph Cugnot, who in 1769 went forth from the Void-Vacon commune in northeastern France with the world’s first self-propelled vehicle, a steam-powered tricycle built like a wagon.

While still dominant in their home market, French cars claim only a small, if loyal, following in the United States. They haven’t been sold here since the early 1990s, despite their significant role in Stellantis, the name given to Fiat Chrysler Automobiles and the French carmaker PSA after their merger last year.

To explore these twin cultural sea changes, I recently set off with a friend for Madison, Conn., to visit and ruminate with one of America’s best-known French expatriates, Jacques Pépin. Arriving in the New World more than 60 years ago, Mr. Pépin, 86, has become one of French gastronomy’s most successful proponents in the United States: chef, cookbook author, TV personality, painter, philanthropist and, more recently, social media star. As a onetime serial owner of French automobiles, he seemed uniquely suited to answer the question: Are these once internationally heralded products of French culture — food and cars — due for a 21st-century renaissance?

Our transport to Connecticut, fittingly, would be a 1965 Peugeot 404, a model that Mr. Pépin once owned and remembers fondly. This one, a seven-seat “Familiale” station wagon bought new by a Canadian diplomat on assignment in Paris, wound up for reasons unknown in a barn in Medicine Hat, Alberta, where it sat untouched for more than 50 years. Fully roadworthy, with less than 25,000 miles on its kilometer-delineated odometer, it oozes the charm of French automobiles at their distinctive best, with creamy smooth mechanicals, seats as comfortable as any divan and legendary, Gallic ride comfort that improbably betters most modern cars, even on the roughest roads.

Our visit begins with a tour of Mr. Pépin’s home and outbuildings on his four wooded acres. Situated between a church and a synagogue, the compound houses two impressively outfitted kitchens, with dazzling arrays of neatly arranged cookware and saucepans. Two studios help extend Mr. Pépin’s brand indefinitely into the future, one with a kitchen used for filming the series and videos, and another for painting the oils, acrylics and mixed-media works that are featured in his books and grace his coveted, handwritten menus.

Setting off in the 404 for lunch, we all arrive in nearby Branford at Le Petit Café, a French bistro. Chef Roy Ip, a Hong Kong native and former student of Mr. Pépin’s at the French Culinary Institute in New York, greets our party, having opened specially on this weekday afternoon for the mentor who 25 years ago helped broker the purchase of the 50-seat cafe. Over a groaning plate of amuse-bouches and loaves of freshly baked bread and butter — “If you have extraordinary bread, extraordinary butter, then there ought to be bread and butter” at every meal, the guest of honor vouchsafes, raising a glass of wine — we sidle up to the delicate topic at hand.

Though he drives a well-used Lexus S.U.V. today, Mr. Pépin’s French car credentials are clearly in order. Tales of his early life in France, where his family was deeply involved in the restaurant business, are peppered with memories automotive. A seminal one concerns the Citroën Traction Avant, an influential sedan built from 1934 to 1957. Developing the car, which was revolutionary for its front-wheel drive and unit-body construction, bankrupted the company’s founder, André Citroen, leading to its takeover by Michelin, the tire maker.

The car’s mention recalls for Mr. Pépin a day during the Second World War when his family left Lyon in his uncle’s Traction Avant to stay at a farm for a while. “My father was gone in the Resistance,” he says. “That car I still remember as a kid, especially the smell. I always loved the Citroëns because of that.”

Afterward, his parents owned a Panhard, an idiosyncratic machine from a small but respected French manufacturer that would fall into the arms of Citroën in 1965, a decade before offbeat Citroën itself would be swallowed — and, critics argued, homogenized — by Peugeot.

Like many Frenchmen after the Second World War and millions elsewhere, Mr. Pépin was smitten by Citroen’s postwar small car, the Deux Chevaux, which he says was the first car his mother had owned.

“Seventy miles to the gallon, or whatever,” he says. “It didn’t go too fast, but we loved it.”

Mr. Pépin’s distaste for excess — notwithstanding his early detours into rich, labor-intensive foods, such as when he cooked at New York City’s Le Pavillon, a onetime pinnacle of American haute cuisine — informed not just the simpler cooking he’d later champion but many of his vehicle choices when he first hit the American highway. In his memoir, he refers, for instance, to the Volkswagen Beetle that he used to thrash down the Long Island Expressway on his way to visit one of his friends, the New York Times food writer Craig Claiborne, on Long Island’s East End. A Peugeot 404 would figure in his commute to work at the Howard Johnson test kitchen in Rego Park, Queens, where he worked for 10 years.

Later, a Renault 5 — an economy subcompact known as LeCar in America — joined Mr. Pépin’s family as his wife Gloria’s daily driver.

He remains, too, a solid supporter of what is perhaps France’s greatest automotive icon, the Citroën DS, which President Charles de Gaulle was riding in when 12 right-wing terrorists tried to assassinate him in 1962, firing 140 bullets at his car as it left central Paris for Orly Airport. The fusillade blew out the DS 19’s rear window and all its tires, yet, owing to its unique hydro-pneumatic suspension, de Gaulle’s driver was able to drive the tireless car and its occupants to safety.

“It saved his life,” Mr. Pépin marvels. “A great car.”

Though Mr. Pépin had been a personal chef to de Gaulle in the 1950s, he did not know him well, he says. “The cook in the kitchen was never interviewed by a magazine or radio, and television barely existed,” he says. “If someone came to the kitchen, it was to complain that something went wrong. The cook was really at the bottom of the social scale.”

That changed in the early 1960s with the arrival of nouvelle cuisine, Mr. Pépin reckons. But not before he had turned down an invitation to cook for the Kennedy White House. (The Kennedys were regulars at Le Pavillon.) His friend René Verdon took the job, sending Mr. Pépin a photo of himself with President John F. Kennedy.

“All of a sudden, now we are genius. But,” he says with a laugh, “you can’t take it too seriously.”

Befriended by a Hall of Fame roster of American foodies, including Mr. Claiborne, Pierre Franey and Julia Child, Mr. Pépin ultimately became a star without the White House association, though his extraordinary innings were almost cut short in the 1970s when he crashed a Ford station wagon while trying to avoid a deer on a back road in upstate New York.

If he hadn’t been driving such a big car, Mr. Pépin believes, “I’d probably be dead.” He ended up with a broken back and 12 fractures and still has a “drag foot,” he says, because of a severed sciatic nerve. His injuries forced him to close his Manhattan soup restaurant, La Potagerie, which served 150 gallons of soup a day, turning over its 102 seats every 18 minutes.

While Chef Ip presents the table with a simple but delicious Salade Niçoise, followed by a finely wrought apple tart, Mr. Pépin turns his attention to the question of France’s diminished influence in the culinary and automotive worlds. He is, I am surprised to learn, in heated agreement — the ship has sailed.

“Certainly when I came to America, French food or ‘continental’ food was what any of the great restaurants were supposed to be, often with a misspelled French menu,” he says. But continued waves of immigration and jet travel that opened up the far corners of the world led to French food’s losing “its primary position.”

“People still like French food just like they like other foods,” he says, adding, “Americans matured and learned about a larger variety of options.”

Mr. Pépin, who calls himself an optimist, hastens to add that he doesn’t see this as a bad thing. He remembers vividly how culinarily grim America was when he arrived, drawn by a youthful enthusiasm for jazz. At first, he marveled at the idea of the supermarket.

“But when I went in, no leek, no shallot, no other herbs, one salad green that was iceberg,” he says. “Now look at America. Extraordinary wine, bread, cheese. Totally another world.”

Indeed, Mr. Pépin, whose wife was Puerto Rican and Cuban, doesn’t even see himself as a “French chef” anymore. His more than 30 cookbooks, he says, “have included recipes for black bean soup with sliced banana and cilantro on top.” He also has a recipe for Southern fried chicken. “So, in a sense, I consider myself a classic American chef,” he says. “Things change.”

During a leisurely afternoon with Mr. Pépin, it becomes clear that while a changing world doesn’t faze him much, he has regrets, his greatest being the loss of loved ones. His father died young in 1965, and his defining sadness, the loss of his wife, Gloria, in December 2020 to cancer weighs heavily.

“The hardest thing is not sharing dinner at night. And that bottle of wine.” He goes quiet for a long moment.

In distilling his reflections on cuisine and cars, the chef notes what he sees as a lamentable trend: the loss of variety, attributable to the motives of corporations.

“There is more food today in the supermarket than there has ever been before,” Mr. Pépin says. “But at the same time, there is more standardization. I try to shop where ordinary people shop, to get the best price. And I cannot go to the supermarket and find chicken backs and necks anymore.”

The same is true, he says, of the automobile industry, where the increasing use of a small pool of multinational suppliers, along with stricter regulations and corporations’ increased reluctance to take chances, has rendered cars ever more similar across brands.

“The special characteristics which made French cars different don’t really exist anymore, even in France,” he says. “They all follow the same aesthetic. Neither French food nor French cars have the same cachet they used to have.”

Mr. Pépin remains philosophical. He mourns the loss of distinctively French cars, but clearly isn’t losing sleep over it. Ditto French food.

As long as “people are getting together” and cooking quality ingredients, he has hope, for “eating together is probably what civilization means.”