I have had a 2010 Enclave for 58000 miles and used all kinds of gas in it. Seems to get best mileage with 89 octane 10% ethanol blend at 1000 ft msl in Iowa summer and winter. I use 87 octane in Colorado at 5000 to 10000 feet. I get about 20 mpg hwy with AWD and travelling at "about" the speed limit. If I slow to 65 it gets about 22 mpg in summer. Not as much difference in winter.
The 2008 Buick Enclave is a gas-powered vehicle.
The 2010 Buick Enclave is a gas-powered vehicle.
The 2012 Buick Enclave is a gas-powered vehicle.
The 2013 Buick Enclave is a gas-powered vehicle.
The 2014 Buick Enclave is a gas-powered vehicle.
The 2011 Buick Enclave is a gas-powered vehicle.
The 2009 Buick Enclave is a gas-powered vehicle.
The gas tank on the 2011 Buick Enclave holds 22.0 gal..
The gas tank on the 2014 Buick Enclave holds 22.0 gal..
The gas tank on the 2009 Buick Enclave holds 22.0 gal..
The gas tank on the 2008 Buick Enclave holds 22.0 gal..
The gas tank on the 2012 Buick Enclave holds 22.0 gal..