Americans turned more optimistic about the economy in May than the previous month, buoyed by low interest rates on home and car purchases.

The University of Michigan says its index of consumer sentiment rose to 94.7 in May, the highest in nearly a year. That's up from 89 in April.

A more optimistic consumer is typically more likely to spend, which drives greater economic growth. Consumer spending accounts for roughly 70 percent of U.S. economic activity. The economy slowed to a crawl in the first three months of this year, growing just 0.8 percent at an annual rate. Yet most analysts expect growth to rebound in the April-June quarter.

Still, the survey detected some notes of caution, stemming from the presidential election, which was the biggest uncertainty cited by consumers.