The 2010 Toyota Avalon is available as a 4-door, 5-seat sedan. Starting at $27,945, the 2010 Toyota Avalon XL is powered by a 3.5L , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 19-mpg in the city and 28-mpg on the highway. The top of the line 2010ToyotaAvalonLimited , priced at $ 35,285 , is powered by a 3.5L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 19-mpg in the city and 28-mpg on the highway.