With gasoline prices declining since peaking in April, Americans are making fuel economy less of a priority, according to a University of Michigan study recently released.

Since the fuel economy of newly purchased vehicles peaked in March, it has slowly been declining. In the U-Michigan report, June's numbers showed another drop from May, declining to 23.6MPG. Even with the drop the numbers remain well above last year's figures, likely as manufacturers make existing engines more fuel efficient. Last year also saw a decline in the index from March through September before jumping to an average of 23.1 MPG in October.

So far in 2012, average fuel economy of newly purchased vehicles has remained between 23.6 MPG and 24.1 MPG, and improvement over the same time frame in 2011 when the averages were between 22.4 MPG and 23.0 MPG.

It serves as a reminder that unless gasoline prices are higher, Americans won't select a vehicle based on its fuel economy. And while gasoline prices have been falling for several months, they may rise to close out the summer months.

Are you buying a new car any time soon? Does fuel economy matter to you when gasoline prices are falling or cheaper?