The 2011 Chevrolet Avalanche 1500 is available as a 4-door, 5-seat regular side. Starting at $36,300, the 2011 Chevrolet Avalanche 1500 LS 4x2 is powered by a 5.3L , 8 -cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 21-mpg on the highway. The top of the line 2011ChevroletAvalanche 1500LTZ 4x4 , priced at $ 49,500 , is powered by a 5.3L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 21-mpg on the highway.