DETROIT - Vehicle owners are keeping their cars and trucks longer as quality improves and the uncertain economy makes new purchases less appealing, according to a study released this week by automotive consulting firm R.L. Polk & Co.
Polk said the median age of cars on U.S. roads was 9.2 years in 2007, tying the previous year's record high. The median is the point at which half the cars were older and half were newer. In 2007, 41.3 percent of all cars were 11 years or older, compared with 40.9 percent the year before.
The median age for trucks and sport utility vehicles rose 4 percent to 7.1 years.
Dave Goebel, a consultant for Polk's aftermarket team, said those numbers are starting to reflect a surge in truck and SUV purchases in the mid to late 1990s.
Purchases of new cars fell 3 percent in the United States in 2007 as a combination of factors, including high gas prices and the housing crisis, weighed on consumers.
But Mr. Goebel said increasing durability, not the economy, is the main reason for rising vehicle age. "Each new model year the technology continues to get better and there are fewer components that fail, so we expect to see these trends continue," he said.
The Polk report was based on a survey of 240.9 million cars and light trucks.