The 2018 Buick Cascada is available as a 2-door, 4-seat convertible. Starting at $33,065, the 2018 Buick Cascada Base is powered by a 1.6L, 4-cylinder engine mated to anautomatic transmission that returns an EPA estimated 21-mpg in the city and 29-mpg on the highway. The top of the line 2018 Buick Cascada Sport Touring, priced at $37,070, is powered by a 1.6L, 4-cylinder engine mated to anautomatic transmission that returns an EPA estimated 21-mpg in the city and 29-mpg on the highway.