Americans are keeping their cars on the road longer than ever before. According to a March 2009 study released by R.L. Polk & Co., the median age of passenger cars in operation was 9.4 years in 2008 - a record high. That means that, assuming a car is bought new and driven 12,000 miles per year (which is about average), many Americans are logging 112,800 miles before selling or trading in their car.

Seems like a lot, right? In fact, according to J.D. Power and Associates, most Americans probably don't make it that long. They say the average length of time owners keep their cars before trading them in is 73 months -- about six years.

Million-Mile Masters

For a few very loyal car owners, however, six years isn't much. Take Irv Gordon, whose 1966 Volvo P1800 made the Guinness Book of Records in 1998 for its incredibly high mileage. Gordon, the car's original owner, has now logged more than 2.6 million miles on trips and in daily driving. In interviews, Gordon attributed his car's extreme longevity to regular maintenance and his use of genuine Volvo parts.

Then there's Wisconsinite Peter Gilbert, who has logged more than a million miles in his 1989 Saab 900 SPG. MSN reports the durable vehicle, now on display in a museum, still features its original engine and turbocharger.

And let's not forget that domestic cars hit the million-mile mark just as often as their foreign competitors. In 2008, Frank Oresnik (coincidentally, another Wisconsinite) was just short of hitting the million-mile mark in his 1991 Chevrolet Silverado truck. Left Lane News reports that the truck has gone though four radiators, three gas tanks, five transmissions and six water pumps, but never a new engine.

Dependability vs. Longevity

Surprisingly enough, Swedish brands, while traditionally known to rack up the miles, aren't exactly known for their dependability. According to the J.D. Power and Associates 2009 Vehicle Dependability Study, Buick and Jaguar rank highest, while Saab and Volvo rank below average. The study measures problems experienced by original owners of three-year-old (2006 model year) vehicles and is based on more than 46,000 individual responses. So how can Volvos and Saabs last so long? The answer is that dependability and longevity aren't interchangeable.

"You could have a car that's structurally very sound and will last a long time but has problems along the way," explains David Sargent, J.D. Power's vice president of automotive research. "In that sense, reliability and durability are very different."

How to Go the Distance

If you love your car, you might dream of making it to the one-million-mile mark, too. But can it be done? The consensus seems to be that with regular maintenance and the necessary parts replacements over the years, most modern cars can go the distance.

According to Edmunds, the top five ways to make your car run "forever" are: Follow your service schedule, check fluids and tire pressure regularly, go easy during startup, use a single high-grade fuel, and drive smart. If you don't know much about maintenance basics, there are plenty of online resources available, as well as your car dealership or your favorite mechanic.

Most experts agree the best way to make your car last longer is to religiously follow the maintenance schedule in your owner's manual. In addition, make sure to check vital fluids every three months (especially engine oil and radiator coolant), pay attention to your car's gauges, regularly wash the car, and store it in a covered place. Even good driving habits can help minimize regular wear and tear.

Longevity or Bust

A few makes have had enough high-mileage success stories that they've created official clubs to commemorate them. Examples include the Honda Mile Makers and Volvo High Mileage clubs, which are open to owners who have logged 100,000 miles or more. There's even an online petition for a Ford high mileage club. As of April 2009, it had 671 online signatures.

Still, just because these automakers have clubs doesn't mean other makes won't last just as long. There's no scientific way to predict which cars or makes will last the longest. Maybe the only way to know is to see for yourself. Keep an open mind, do your research, and maintain, maintain, maintain - and your million-mile ride just might make the news next.