I just ran the fuel numbers for our recent grand trip to Missouri. For 4380km in a Honda Civic DX, we used about 292 litres of fuel. That works out to be 6.7l/100km (or 42.3 / 35.3 UK / US mpg). That’s not quite as good as I’d hoped; I’ll put it down to driving a little fast on very chunky snow tyres.
At least it’s better than last time …