The University of Michigan's preliminary September consumer sentiment index reading was 79.2, compared to the final August 74.3, according to market sources.
The expectations index was 73.4, compared to 65.1 in August.
The current conditions index was 88.3, compared to 88.7 in August.
Economists polled by Thomson Reuters had predicted a 74.0 reading for the main index, 87.0 for current conditions and 65.0 for expectations.
The five-year inflation expectation index was 2.8%, compared to 3.0% in August, while the one-year inflation expectation index was 3.5%, compared to 3.6% in August.
The University of Michigan index is not released to the press, but only to paying subscribers.