The MC20 is no exception to the rule that powerful sports vehicles don’t have outstanding gas mileage. The MC20 has a combined city/highway fuel economy of 15 mpg. That’s a slight improvement over the ratings of, say, the discontinued Mercedes-AMG GT, which got only 22 mpg on the interstate in its most fuel-efficient configuration. When we finally get the MC20 on our real-world highway fuel efficiency test route, we’ll report back with our findings.