Consumers borrowed more in January to purchase new cars but were once again frugal with their credit cards, offering a mixed sign of their confidence in the economy.

Borrowing rose 2.5 percent, or by $5 billion, the Federal Reserve said yesterday It was the fourth-consecutive monthly gain and it increased total consumer debt to $2.41 trillion.

Strong car sales drove the increase. The category that includes auto loans rose 6.9 percent.

But credit card debt fell 6.4 percent in January — the 28th decline in 29 months — to lowest level since September 2004.

Americans had increased their use of plastic in December for the first time since the financial crisis. But they cut back the following month, even though a Social Security tax cut is giving most households an extra $1,000 to 2,000 this year.