DETROIT — She wants a new car, but Pamela Davies is still driving the very first one she purchased.

Even with 81,000 miles on her 2001 Toyota RAV4, the stay-at-home mother of two young children isn’t ready to give it up. Her husband’s 1999 Corolla, with 136,000 miles on it, is fine for now, too.

“We had originally planned to replace the RAV4 with a minivan when we had a second kid, but then I realized I could fit two car seats in it and put it off,” said the North Chelmsford, Mass., resident. “Until one or both of my kids’ knees are squished up around their ears from being crammed in the back seat, or the car stops running, it’s staying with us.”

Davies said her family could afford a new car, but the two they have are fully paid for. She and her husband would rather not take on a monthly car payment as they save for college and retirement.

The recession has forced the Davies and many other Americans to rethink their spending habits. One result: They’re making their old cars last longer.

According to J.D. Power and Associates, the average age of vehicles traded in at U.S. car dealerships in February was 6.1 years. That’s up from 5.6 years a year earlier. That trend is expected to contribute to another month of depressed auto sales when carmakers report their March results on Wednesday.

Consumers are starting to see vehicles as long-term investments, said Trevor Traina, founder and chairman of the car ownership Web site DriverSide.com. Automakers for the most part have stopped offering leases, which allowed people to drive a new vehicle for $200 or $300 a month and repeat the cycle every few years. People are taking better care of their old wheels instead.

Davies, 31, has been eyeing a new $34,700 Toyota Highlander hybrid. Instead of giving in to the impulse, the family spent about $1,000 last year on car maintenance, including four new tires, a few oil changes and regularly scheduled tune-ups.

“We’re holding on until the bitter end,” Davies said. The family would have to get another car should their Corolla die, but she said they would purchase a used one, or something less expensive than the Highlander.

Car owners such as Davies are one reason auto parts stores such as AutoZone Inc., Advance Auto Parts Inc. and O’Reilly Automotive Inc. have seen rising sales.

They’re also one reason the new car market is in the tank.

“The desire to own a car for two to three years is dead,” Traina said. “It’s like people have woken up from some kind of consumer dream of flipping a car the way you change clothes.”