WASHINGTON - Americans borrowed more in June to buy cars and attend schools. But they were frugal again with their credit cards, as many remain wary of taking on high-interest debt.

Consumers increased their borrowing $13.8 billion in June from May to a seasonally adjusted $2.85 trillion, the Federal Reserve said Wednesday in its monthly report on consumer credit. That's the highest level ever.

The category that includes credit card debt dropped $2.7 billion in June and remains 16.5 percent below its July 2008 peak.

Borrowing for autos and student loans rose $16.5 billion in June. Gains in this category have lifted overall consumer credit to record levels in all but one month since June 2011.

Since January 2011, the measure of student and auto loans has risen $312.6 billion. During that same 2.5-year period, credit card debt has increased just $16 billion.

The Federal Reserve's consumer credit report does not separate student loans and auto loans. But the Federal Reserve Bank of New York tracks consumer credit on a quarterly basis. Those reports show that student loan debt has been the biggest driver of borrowing since the Great Recession officially ended in June 2009. In part, that's because many unemployed Americans have returned to school for training in hopes of landing a job.

More credit card borrowing could help boost consumer spending, which accounts for 70 percent of economic activity. But many consumers have been hesitant to run up high-interest debt since the Great Recession ended. And this year consumers have been hit by higher Social Security taxes.

The economy grew at a lackluster annual rate of 1.4 percent in the first six months of this year. Economists expect growth is accelerating to an annual rate of around 2.5 percent in the second half of this year, as the impact of higher taxes and spending cuts begin to fade. Also, hiring gains are expected to boost income, supporting more spending.

The economy has been adding jobs this year at a steady but inconsistent pace. In July, employers added 162,000 jobs. While solid, that's much slower than the average pace of 192,000 new jobs a month so far this year. And many of the jobs added last month were low-paying or part-time.

The unemployment rate fell in July to 7.4 percent, down from 7.6 percent in June.

The Federal Reserve's borrowing report covers auto loans, student loans and credit cards. It excludes mortgages, home equity loans and other loans related to real estate.