I'm really disappointed with the efficiency of the GM motor in the Sling. Drove to Laredo (about 300 miles) and reset the calculator. I avg about 18 mpg when driving at the speed I'd like to 90-100mph in 5th. But it freaking struggles to cruise at that speed...
Had to drop to 75-80mph to get to 20-21mpg...
I don't care in the city when I'm launching and driving hard, but highway cruising? Come on man!!!