So have had my car a month now, it's a 2015 272bhp Black Edition, totally loving it of course but just realised it's doing 23mpg if I have my calculations right. Surely that's way too low? Not doing much in way of long drives or being too heavy footed, but even still. I'm getting 400 miles for a full tank which is costing me between £70-80 each time. That sound off to anyone?